US 5088464

I'll search for this specific patent number and check for any CAFC docket activity.

Let me check for litigation/CAFC activity and current ownership more specifically.

Summary — US Patent 5,088,464

Important scope note: I searched for the literal identifier "5088464" / "5,088,464." The only distractors returned were JP 5088464 B2 (a Mitsubishi Materials sputtering-target patent that issued 2012-12-05 — an entirely different patent in a different jurisdiction and technology) and unrelated "464"-suffixed US patents (e.g., the C‑fold mailer patent discussed in Moore v. ..., Fed. Cir. 2000). Neither is the subject patent. All statements below relate to US 5,088,464.

Bibliographic data (per Google Patents / Justia)

Assignee chain (per recorded assignments): Echlin, Inc. → Mr. Gasket, Inc. (2001, nunc pro tunc) → Prestolite Wire Corporation (2007) → Prestolite Wire LLC (change of name, 2008) → ACCEL Performance Group LLC (release/security transactions; ACCEL appears in later collateral filings). Multiple security interests were recorded (U.S. Bank; UBS AG; AEA Debt Management LP) and released 2021. The "General Cable Industries Inc" listing appears to reflect a corporate relationship rather than a direct recorded assignment to that entity for this patent — treat as uncertain.

Abstract (as issued)

A system for managing operation of a V‑twin motorcycle engine that includes a throttle body having an air intake manifold adapted to be mounted to the engine over the cylinder intake ports, and a throttle for operator control of combustion air into the manifold. A pair of fuel injectors are mounted on the throttle body and respond to electronic injector control signals to inject fuel into the manifold adjacent the intake ports. A fuel pump delivers fuel under pressure from a supply, and a pressure regulator supplies fuel at regulated pressure to the injectors. An engine speed sensor supplies a signal as a function of engine speed, and a pressure sensor coupled to the manifold supplies a signal as a function of manifold air pressure. An electronic controller includes a memory storing a plurality of injector pulse width control parameters as a look‑up table addressable as a function of the speed and pressure signals; the injector control signals are generated as a function of those parameters.

Plain-language overview of the independent claims

The patent has 19 claims with two independent claims: claim 1 and claim 13.

Independent Claim 1 — Electronic fuel-injection management system for a motorcycle engine

A motorcycle engine management system comprising, in combination:

1. Throttle body with integrated intake manifold mountable to the motorcycle engine, with an operator-controlled throttle metering combustion air.
2. At least one fuel injector mounted on the throttle body, driven by electronic injector control signals to inject fuel into the manifold.
3. Pressurized fuel delivery — an electric fuel pump plus a pressure regulator feeding fuel at regulated pressure to the injector.
4. Engine speed sensor producing an electrical speed signal.
5. Manifold pressure sensor producing an electrical pressure signal.
6. Electronic control unit containing memory that stores injector pulse-width control parameters as a look-up table indexed by the speed and pressure signals, plus means for generating the injector control signals from those parameters (i.e., speed-density style table-based fueling on a motorcycle).

Independent Claim 13 — V-twin-specific implementation with simultaneous double-fire

Focused on a V-twin motorcycle engine:

1. Throttle body with intake manifold and operator throttle, as above.
2. A pair of fuel injectors mounted on the manifold, respectively adjacent each cylinder's intake port.
3. Fuel pump plus pressure regulator feeding both injectors.
4. Engine speed sensor that provides a pulse at a predetermined angle before top-dead-center for each cylinder (the spec describes a Hall-effect camshaft sensor producing pulses at 45° BTDC).
5. Manifold air pressure sensor.
6. Electronic control means that (a) stores injector pulse-width parameters as a look-up table indexed by speed and pressure, (b) retrieves a base injector activation time, and (c) in response to each speed pulse, activates both injectors for a time varying with the base time (the "double-fire" simultaneous-injection scheme).

Dependent claims sketch: Claim 2 adds a second speed/pressure-indexed look-up table for ignition advance angle. Claims 3–5 add a fuel-enrichment source (claim 4 specifies a pressurized N₂O container) with a throttle-body-mounted valve, and automatic increased fueling during enrichment. Claims 6–9 add a throttle-position sensor and operator-adjustable idle/WOT fueling modifications, plus battery-voltage compensation of injector timing. Claims 10–12 add oxygen-sensor closed-loop A/F control (target stoichiometric 14.7), engine-temperature and intake-air-temperature compensation. Claims 14–19 add supplemental-sensor correction of base injection time, ignition control from the second table with double-fire spark delivery, and the N₂O enrichment features (automatic fuel enrichment and automatic spark retard when nitrous is delivered).

Litigation / CAFC 2026 docket check

• I found no evidence of any 2026 (or other) Court of Appeals for the Federal Circuit appeal, district-court action, ITC proceeding, or PTAB (IPR/PGR) matter involving US 5,088,464. Keyword searches for the number in combination with Federal Circuit/docket/litigation/appeal terms returned no such case.
• This is consistent with the patent's status: it expired 2011-06-24 (anticipated 20-year term), and it is more than a decade past expiration.
• Uncertainty statement: I cannot conclusively rule out a docket entry that is not indexed by the tools available to me. The absence of results should be read as "not found," not as an affirmative certification that no such proceeding ever existed.

Caveats

• Bibliographic fields above are drawn from the Google Patents/Justia records for US 5,088,464A; the record itself notes that some assignee data and legal-status labels are "assumptions" and not legal conclusions. For definitive current ownership or chain of title, verify with USPTO Patent Center/Assignment records.

I'll search for litigation involving US patent 5088464.

Let me search more targeted litigation sources.

Let me check the Unified Patents portal and other litigation-specific databases.

Litigation Search Report — U.S. Patent No. 5,088,464

Bottom line: I found no record of any litigation involving U.S. Patent No. 5,088,464. Based on the searches I was able to run and complete, no district court case, Federal Circuit appeal, ITC investigation, or PTAB proceeding involving the '464 patent is publicly reported. I want to be explicit that this is a negative finding from limited search coverage — see the caveats below.

Patent identification (for disambiguation)

The number 5088464 is a U.S. patent number only when read as US 5,088,464:

• Title: "Motorcycle engine management system"
• Inventor: John D. Meaney
• Filed: June 24, 1991 (App. No. 07/720,015)
• Granted: February 18, 1992
• Original assignee: Echlin, Inc. (Branford, Connecticut)
• Status: Expired – lifetime (anticipated expiration June 24, 2011)
• Continuation-in-part: US 5,174,263 (App. No. 07/835,609, filed Feb. 13, 1992), also "Motorcycle engine management system"

Cases found

None. I could not identify any plaintiff, defendant, jurisdiction, case number, filing date, or outcome for this patent because no case was located.

Why the results are negative, and what the searches did surface

Searches for "5088464" returned several false positives on the bare numeric string that are not the U.S. patent and must not be conflated with it:

• JP 5088464 B2 — a Japanese patent (Mitsubishi Materials) on sputtering targets for optical recording media; unrelated technology and a different jurisdiction's numbering series.
• UK insolvency/gazette entries and a retail jewelry catalog line item — incidental uses of "5088464" as an internal or case reference number.

The Google Patents page for US 5,088,464 (the authoritative text you supplied) contains no litigation section, and the "Cited By" list is patent-to-patent citation activity, not litigation. Similarly, the Unified Patents result surfaced the sibling patent US-5174263-A (parent company General Cable Industries; original assignee Echlin Inc.), not any suit over the '464.

Post-issuance record — ownership and collateral, not litigation

The assignment history reflects corporate chain-of-title and security-interest transactions, which are sometimes mistaken for litigation activity. These are not lawsuits:

• 2001 — Echlin Inc. → Mr. Gasket, Inc. (nunc pro tunc assignment)
• 2007 — Mr. Gasket, Inc. → Prestolite Wire Corporation; later Prestolite Wire LLC (name change)
• Security agreements/releases recorded with U.S. Bank National Association, AEA Debt Management LP (second lien), and UBS AG, Stamford Branch (first lien) involving ACCEL Performance Group LLC and affiliated Holley Performance Products / MSD / Powerteq / Racepak / Flowmaster entities
• 2015 / 2017 / 2021 — releases by secured parties

Separately, I noted a California Air Resources Board Executive Order D-332-1 (May 25, 1995) exempting the "Harley Davidson Thunder Twin Fuel Injection" made by Echlin, Inc. and marketed by ACCEL Motorcycle Products (ECU part no. 5558; throttle body part no. 5587; injectors part no. 5521). This is an emissions-compliance action, not patent litigation.

Caveats and recommended verification

I was unable to complete additional targeted queries (against the Unified Patents litigation case list, PACER, and Docket Navigator) before running out of search steps, and I did not complete a direct query of the Unified Patents litigation/caselist page. Therefore:

• Treat this as "no litigation found in the sources checked," not as a definitive absence of litigation.
• To close the gap, I recommend a direct PACER docket search on the patent number, a Unified Patents litigation search, and a Lex Machina / Docket Navigator query. Note also that because the '464 patent expired June 24, 2011, any litigation would necessarily predate expiry, and older 1990s-era cases may not be fully digitized.

I am not able to confirm any case details with high confidence, and I decline to invent them. If you can share a litigation database export or a specific docket number, I can analyze it further.

Proceedings overview

No AIA trial proceedings are on file for US 5,088,464. The USPTO Open Data Portal returns zero IPR, PGR, or CBM proceedings as of the most recent ingest, and independent web searching (PTAB public-information pages, PTAB decision databases, and Federal Circuit/CourtListener coverage) surfaced no petition, no institution decision, no Final Written Decision, and no appeal involving this patent. Total count: 0 — 0 active, 0 claims invalidated, 0 claims sustained, 0 settled, 0 institution denials.

Bottom-line defensive posture: the absence of PTAB activity here is not a "hardened patent" signal in the usual sense — it is a function of the patent's age and expired status. US 5,088,464 issued 1992-02-18 from a 1991-06-24 filing and expired 2011-06-24 (Google Patents legal-status entry: "Anticipated expiration," "Expired - Lifetime"). It is a pre-AIA patent (filed before 2013-03-16), so PGR was never available, and it is a mechanical/engine-control patent, so CBM was never available either. IPR became available only on 2012-09-16 — roughly 15 months after this patent expired — which materially dampens the incentive to file. A defendant today is not facing a patent that has been tested and survived before the Board; it is facing a long-expired patent with no remaining term to protect, which is a different (and much weaker) posture for any plaintiff.

No proceedings to report

There is no {PROCEEDING_NUMBER} to populate. Per the structured "PTAB proceedings on file" block and confirmed by search, zero AIA trial petitions have ever been filed against US 5,088,464. I am not aware of, and could not locate, any of the following:

• Type: none (no IPR / PGR / CBM)
• Filed: N/A
• Status: N/A
• Judge panel: N/A
• Petition grounds: N/A
• Institution decision: N/A
• Final Written Decision: N/A — no claim of this patent has ever been canceled or confirmed by the Board
• Settlement / termination: N/A
• Appeal: N/A — no PTAB decision exists to appeal to the Federal Circuit
• Defensive value: N/A

I will not invent a proceeding number, panel, or disposition to fill this section. If a proceeding does exist that the ODP has not yet indexed, it is not discoverable through the sources available here; treat that possibility as low-probability given the patent's 2011 expiration.

Related-patent note (not a proceeding on this patent): US 5,088,464 has a continuation-in-part child, US 5,174,263 ("Motorcycle engine management system," filed 1992-02-13, granted 1992-12-29, also Echlin, Inc.), which appears on the '464 patent's "Related Child Applications" list. No AIA trial activity was found against the '263 patent either, but a defendant reviewing the family should verify that separately through PTAB E2E rather than relying on this analysis.

Strategic summary

Claim status of US 5,088,464. Because no IPR, PGR, or CBM was ever instituted, none of claims 1–19 has been canceled, and none has been confirmed by the Board. On paper the full claim set (claims 1–19, including independent claims 1 and 13) remains as issued. But that "untested and intact" framing is misleading in practice: the patent's 20-year term from its 1991-06-24 filing ran out on 2011-06-24, and its status is "Expired - Lifetime." There is no live patent right to assert for any conduct occurring on or after that date. Claims 1–19 are, in effect, moot rather than sustained — no tribunal has blessed them, and none needs to, because there is no enforceable term left to litigate over.

Damage/assertion window. Even for historical conduct, 35 U.S.C. § 286 caps recovery at six years before suit. With today's date being 2026-09-29, that lookback reaches back only to roughly 2020-09-29 — more than nine years after the patent expired. Any complaint asserting the '464 patent now has a severe, threshold problem: there is no period of alleged infringement within the statutory damages window. That is a stronger and cheaper defense than any IPR outcome would have been, and it should be raised first.

Estoppel landscape. § 315(e)(2) estoppel is irrelevant here — it attaches only to a petitioner that obtained an instituted IPR, and no such petitioner exists. There is therefore no petitioner, privy, or real party in interest who is barred. Conversely, no one has been estopped in the patent owner's favor either. For a current defendant, all invalidity theories remain available in district court (subject to the usual § 282 burden and any reexamination history): § 102/§ 103 over the nine examiner-cited references, plus any art the examiner never saw. Note that the patent is pre-AIA, so the pre-AIA § 102(b) one-year on-sale/public-use bar and pre-AIA § 102(a)/(e) rules apply — and the claims are also potentially vulnerable under pre-AIA § 112 for the functional, result-oriented limitations in the look-up-table claims, though 112 is not an IPR ground.

Pattern signals. There are none to report: no repeat petitioner (there are no petitioners at all), no aggressive PTAB appellate strategy by the patent owner (Patents: Echlin, Inc. → Mr. Gasket, Inc. → Prestolite Wire → ACCEL Performance Group LLC, now under the Holley/MSD performance-products umbrella per the recorded assignments — a chain of corporate transfers, not litigation activity), and no defensive aggregator such as Unified Patents in the chain. The recorded assignment history is exclusively security agreements, nunc pro tunc assignments, releases, and name changes; it contains no licensing or litigation enforcement activity. That is consistent with a patent that was monetized (if at all) long ago and is now simply an asset in an aftermarket-performance portfolio.

Recommended next steps

1. Lead with expiration, not invalidity. This patent expired 2011-06-24. Demand letters or complaints citing US 5,088,464 are, on their face, asserting an expired patent. Verify the expiration and the Patent Term Adjustment/extension status directly on USPTO PatentCenter for 5,088,464 and confirm no terminal disclaimer or reissue extends the term.

2. Check the § 286 window. Compute the six-year lookback from the date of any suit. If the accused conduct post-dates 2011-06-24, there is no recoverable infringement period; that is a dispositive motion rather than a merits defense.

3. If you still need an invalidity record, reexamination — not IPR — is the realistic vehicle. IPR is generally a poor fit for an expired patent because there is no term to defend against, and the Board's incentive/authority is constrained here. An ex parte reexamination request (which can be filed by anyone, at any time, on § 102/§ 103 patent-and-printed-publication art) remains available and would produce a public cancellation record. The nine references cited by the examiner on the face of the patent — e.g., US 4,947,816 (Japan Electronic Control Systems), US 4,947,820 (Toyota), US 4,962,739 and US 4,996,958 (Mitsubishi), US 4,967,711 / US 4,967,715 (Fuji Jukogyo), US 5,002,031 (Mitsubishi), US 5,003,950 (Toyota), and US 5,016,595 (Toyota) — are the starting point for both examiner-cited and cumulative art, and the prosecution histories of those pre-AIA engine-control patents (all 1990–1991) are a rich source of § 103 combinations against claims 1–19.

4. Read the '464 specification for § 112 ammunition. The patent itself concedes that "[s]pecific control algorithms for control of fuel injector timing as a function of one or more sensor outputs do not per se form part of the present invention" and repeatedly incorporates by reference U.S. Application Ser. No. 07/429,789 (filed 1989-10-26) for the operative control logic. The claims nonetheless recite functional means-plus-function-style limitations ("means for generating said injector control signals as a function of said parameters"). Under pre-AIA § 112 ¶ 6 (now § 112(f)), the corresponding structure resides largely in the incorporated application, raising indefiniteness and enablement exposure. This is a district-court/Litigation ground, not an IPR ground (§ 311(b) limits IPR to § 102/§ 103), so preserve it.

5. Do not spend IPR budget chasing a proceeding that does not exist. Because there is no PTAB activity on file, there is no FWD to link, no disposition to quote, and no estoppel to exploit. If you want to confirm this against the live docket before relying on it, check the USPTO PTAB E2E / PTAB Decisions portal and CourtListener's PTAB and CAFC dockets for the patent number, and additionally check the child patent US 5,174,263 and the parent application family. Absent a hit there, the correct representation to a client or a court is simply: "US 5,088,464 has never been the subject of an AIA trial proceeding, and it expired in 2011."

I'll search for the assignment records and correspondent data before writing the analysis.

Assignment & Ownership Analysis — US 5,088,464

Scope note: The reel/frame data below is taken from the Google Patents legal-events record embedded in the authoritative patent text supplied for this analysis (the same records that underlie the USPTO Assignment Center). Two gaps I could not close are stated explicitly rather than filled by inference: (a) correspondent-of-record fields were not exposed by any source I could reach — Google Patents lists reel/frame, conveyance, and parties but not the recording attorney; and (b) the Assignment Center's index pages at assignmentcenter.uspto.gov / assignment.uspto.gov/patent/index.html were not retrievable in a form that returns the correspondent field. Signal #3 below is therefore marked unclear, not "not present."

Inventors

• The executed assignment (reel 005759/0162) is dated 1991-06-05 and records Meaney as assignor to Echlin, Inc., i.e. ~19 days before the 1991-06-24 filing date. The application was filed and the assignment recorded the same day (US 07/720,015). This is the textbook employee "ASSIGNMENT OF INTEREST" executed pre-filing, not an inventor hold-back.
• No fire-sale precursor pattern. There is no evidence Meaney (or any other inventor) departed Echlin within 12 months of filing; he is the only inventor, and no later assignment list shows him as an assignor to any unrelated entity. The "inventors bail out early" tell is absent.
• Meaney's name does not recur as an inventor on the other patents in the later-predecessor family that I could see; this appears to be a one-patent contribution by a single corporate engineer.

Original assignee

Echlin, Inc. (Connecticut), named on the issued patent via reel 005759/0162.

• Primary line of business: automotive aftermarket parts — ignition, fuel, and emission-control components ("under the hood" / engine-management parts), plus brakes, chassis, filtration, and fluid-handling systems. Echlin was one of the largest independent automotive aftermarket suppliers (1997 sales ≈ $3.6B).
• Did they ship a product embodying the claims? Yes — strong documentary evidence. California Air Resources Board Executive Order D-332-1 (1995-05-25) exempted the "Harley-Davidson Thunder Twin Fuel Injection" system made by Echlin, Inc. and marketed by ACCEL Motorcycle Products (ECU part no. 5558; throttle body part no. 5587; injectors part no. 5521). This maps almost element-for-element onto independent claim 1 (throttle body + manifold, injectors, electric pump + regulator, speed sensor, MAP sensor, ECU with speed/pressure-indexed pulse-width table) and claim 13 (V-twin). The patent was commercialized, not warehoused. (Note the prior sections' characterization of D-332-1 as an emissions action, not litigation — correct, and it doubles here as commercialization evidence.)
• Current status: acquired/dissolved as an independent entity. Echo Acquisition Corp. (a Dana Corp. subsidiary) merged into Echlin on 1998-07-09; Echlin survived as a wholly-owned Dana subsidiary (~$3.9B stock-for-stock merger, Dana's largest-ever). Dana later sold the Mr. Gasket operation in 2001 and itself filed Chapter 11 in 2006 — but note the '464 chain had already exited Dana by then (see timeline).

Assignment timeline

All entries are recorded post-issuance events on the '464 docket unless noted. Execution/effective dates in parentheses are those shown in the record.

1. 1991-06-05 (exec.) / recorded 1991-06-24 — Reel 005759/0162

• Conveyance: Assignment ("ASSIGNMENT OF INTEREST")
• Assignor: John D. Meaney
• Assignee: Echlin, Inc. (Connecticut)
• Correspondent: not available in reachable sources
• Context: routine pre-filing inventor-to-employer assignment; oil/patent title cleared before issuance.

2. 2001-03-19 (eff.) / recorded 2001-03-28 — Reel 011731/0411

• Conveyance: Nunc pro tunc assignment
• Assignor: Echlin Inc. (Dana subsidiary)
• Assignee: Mr. Gasket, Inc. (Ohio)
• Correspondent: not available
• Context: carve-out divestiture — Dana sold the Mr. Gasket Performance Group (including the ACCEL and ACCEL Motorcycle brands) to Performance Products Industries LLC (PPI) of Brooklyn, Ohio, completed 2001-03-29 (Dana recorded a ~$13M after-tax loss). "Nunc pro tunc" papered the transfer back to the deal effective date.

3. 2001-03-29 (eff.) / recorded 2001-04-02 — Reel 011675/0299

• Conveyance: Security Agreement
• Assignor: Mr. Gasket, Inc.
• Assignee/holder: Echlin Inc. (Ohio)
• Correspondent: not available
• Context: seller financing / transitional securitization — Echlin (the Dana side) retained a security interest in the divested Mr. Gasket assets. (Cross-check flag: the near-identical Echlin/Mr. Gasket security agreement on sibling patent US 5,575,367 is recorded at reel 011675/0248, not 0299. Echlin recorded a long series of parallel security agreements in the same 011675 reel run across its portfolio; the small frame offset is expected, but if you need the exact instrument, pull both frames.)

4. 2001-12-14 (eff.) / recorded 2002-01-18 — Reel 012506/0794

• Conveyance: Release of Security Agreement
• Assignor: Echlin Inc.
• Beneficiary: Mr. Gasket, Inc.
• Correspondent: not available
• Context: clean-up — release of the lien recorded at link 3. (Same reel/frame 012506/0794 recurs on sibling patents US 5,829,422 and US 5,575,367, confirming this was a portfolio-wide release instrument, not patent-specific.)

5. 2007-07-31 (eff.) / recorded 2007-08-31 — Reel 019773/0517

• Conveyance: Assignment of Interest
• Assignor: Mr. Gasket, Inc.
• Assignee: Prestolite Wire Corporation (Michigan)
• Correspondent: not available
• Context: consolidation into the Prestolite/ACCEL performance-parts platform (Mr. Gasket was already operating under the "Prestolite Performance" brand umbrella).

6. 2007-07-31 (eff.) / recorded 2007-12-20 — Reel 020279/0079

• Conveyance: Security Agreement
• Assignor: Prestolite Wire Corporation
• Holder: U.S. Bank National Association (Minnesota)
• Correspondent: not available
• Context: corporate credit facility — blanket lien granted over the transferred IP.

7. 2007-12-31 (eff.) / recorded 2008-01-15 — Reel 020362/0653

• Conveyance: Change of Name
• Assignor: Prestolite Wire Corporation
• Assignee: Prestolite Wire LLC (Michigan)
• Correspondent: not available
• Context: internal reorganization only — entity conversion, no change in beneficial ownership.

⚠ Contradiction / gap to flag: Sibling patents in the same family (US 5,829,422 and US 5,575,367) show a further assignment — Prestolite Wire LLC → Prestolite Performance LLC (Ohio), reel 027895/0335, effective 2011-12-31. That link is not enumerated in the '464 legal-events record, which jumps straight from the 2008 name change to the 2015 release. Either the '464 was omitted from the 027895/0335 instrument, or Google Patents' event list for the '464 is incomplete. Do not treat "Prestolite Performance LLC" as confirmed in this chain — verify reel 027895/0335 directly before relying on it.

8. 2015-08-17 (eff.) / recorded 2015-08-18 — Reel 036378/0006

• Conveyance: Release by Secured Party
• Assignor/secured party: U.S. National Bank Association (almost certainly the U.S. Bank National Association of link 6; the record's "National" vs "Bank National" ordering looks like a transcription variant)
• Party of record (owner side): ACCEL Performance Group LLC (Ohio)
• Correspondent: not available
• Context: lien release — and the first event naming ACCEL Performance Group LLC as the operative owner-side entity. (ACCEL Performance Group is a real, product-shipping performance-parts manufacturer — Mr. Gasket, ACCEL, Hays, Lakewood, Mallory, QuickTime, Prestolite ProConnect brands — and had formally adopted that name in 2013 after operating as Prestolite Performance.)

9. 2012-11-02 (eff.) / recorded 2017-06-02 — Reel 042672/0422

• Conveyance: Release by Secured Party
• Assignor/secured party: U.S. Bank National Association
• Party of record: Prestolite Wire LLC
• Correspondent: not available
• Context: late-recorded lien release (executed 2012, recorded 2017) — administrative clean-up of the 2007 credit facility.

10. 2018-10-26 (eff.) / recorded 2018-11-06 — Reel 047429/0343

• Conveyance: Security Interest (first lien)
• Assignors: Flowmaster, Inc.; APR, LLC; ACCEL Performance Group LLC; and others (Holley-affiliated group)
• Holder: UBS AG, Stamford Branch, as First Lien Collateral Agent
• Correspondent: not available
• Context: group-level leveraged securitization — cross-collateralized lien covering the entire Holley performance-parts family (Holley Performance Products, MSD LLC, Powerteq LLC, Racepak LLC, Flowmaster, APR, ACCEL). Not a title transfer.

11. 2018-10-26 (eff.) / recorded 2018-11-18 — Reel 048147/0510

• Conveyance: Security Interest (second lien)
• Assignors: same Holley-affiliated group
• Holder: AEA Debt Management LP, as Second Lien Collateral Agent
• Correspondent: not available
• Context: second-lien tranche of the same 2018 financing.

12. 2018-10-26 (eff.) / recorded 2018-11-18 — Reel 048475/0125

• Conveyance: Corrective Assignment (deletes patent numbers erroneously included in reel 047429/0343)
• Assignor: group obligors; UBS AG, Stamford Branch confirms the corrected security interest
• Correspondent: not available
• Context: record correction — a routine scrub of the first-lien filing's patent schedule.

13. 2021-11-18 (eff.) / recorded 2021-11-24 — Reel 058944/0279

• Conveyance: Release by Secured Party
• Secured party/assignor: AEA Debt Management LP, as Second Lien Collateral Agent
• Parties of record: MSD LLC; ACCEL Performance Group LLC; Holley Performance Systems, Inc.; Powerteq LLC; APR, LLC; High Performance Industries, Inc.; Racepak LLC; Holley Performance Products Inc.; Flowmaster, Inc.
• Correspondent: not available
• Context: lien discharge on refinancing/repayment.

14. 2021-11-18 (eff.) / recorded 2021-11-24 — Reel 058948/0926

• Conveyance: Release by Secured Party
• Secured party/assignor: UBS AG, Stamford Branch, as First Lien Collateral Agent
• Parties of record: same Holley/ACCEL group
• Correspondent: not available
• Context: lien discharge — parallel release of the first-lien tranche. After this, the record shows no further transfers; the patent expired 2011-06-24.

Timeline diagram

timeline
    title Ownership of US 5088464
    1991 : Meaney assigns to Echlin Inc
    1998 : Echlin merged into Dana Corp
    2001 : Echlin assigns to Mr Gasket Inc
         : Echlin takes security interest
         : Dana sells Mr Gasket to PPI
    2002 : Security interest released
    2007 : Assigned to Prestolite Wire Corp
         : Security agreement with US Bank
    2008 : Name change to Prestolite Wire LLC
    2011 : Patent expires by term
    2015 : US Bank lien released
    2017 : Late US Bank release recorded
    2018 : UBS first lien security interest
         : AEA second lien security interest
    2021 : First and second lien releases

(The 1998 Echlin/Dana entry is a merger by operation of law rather than a patent-level recording, but it explains the 2001 assignor identity.)

NPE / troll-pattern signals

1. Shell-entity transfer — NOT PRESENT.
Every assignee in the chain is a product-shipping manufacturer: Echlin, Inc. (automotive aftermarket); Mr. Gasket, Inc. (gaskets/performance parts, 310 employees, Cleveland OH + Carson City NV); Prestolite Wire Corporation/LLC (wire and performance-parts); ACCEL Performance Group LLC (ACCEL, Mr. Gasket, Hays, Lakewood, Mallory brands). No assignee carries an "IP / Patents / Licensing / Holdings / Ventures" suffix, none is a single-purpose Delaware/Texas LLC, and none is tied to a registered-agent service address on the face of the record. The 2001 Mr. Gasket transfer (reel 011731/0411) went to a buyer of a live $66M-revenue business, not to a holding shell.

2. Known asserter in the chain — NOT PRESENT.
None of Echlin, Mr. Gasket, Prestolite Wire, Prestolite Performance, or ACCEL Performance Group appears on the asserter directories named in the brief (Acacia, Marathon, Intellectual Ventures, IPNav, Wi-LAN, Mosaid/Conversant, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, Document Generation Corp, Spangenberg entities) or in RPX/Unified high-frequency-plaintiff lists as far as my searches reached. The 2018 collateral group (Holley Performance Products, MSD, Powerteq, Racepak, Flowmaster, APR, ACCEL) is an operating performance-parts conglomerate, not an NPE aggregation.

3. Repeat correspondent across the chain — UNCLEAR.
The correspondent-of-record field is not exposed by any source I could retrieve (Google Patents records the reel/frame and parties only; the USPTO Assignment Center correspondent field was not reachable in indexed form). I will not infer recurrence from the fact that the same large patent-recording vendors (e.g., the firms that service Fortune-500 IP departments) file these instruments. Action item: pull the correspondent field per reel/frame from assignmentcenter.uspto.gov — for a chain this long (14 recordings over 30 years) a single recurring recording attorney would be a meaningful tell, but I have no evidence either way.

4. Cascading transfers — NOT PRESENT (as an NPE tell).
The 2018 cluster (reel 047429/0343, 048147/0510, 048475/0125) is a three-record securitization of a single financing dated 2018-10-26, not a chain of ownership transfers through successive shells. Ownership moved through genuine corporate buyers in 1991, 2001, and 2007 — a slow 16-year arc, the opposite of a <24-month shell cascade.

5. Pre-litigation transfer — NOT PRESENT / NOT APPLICABLE.
Per the litigation section already generated, no infringement suit, ITC action, PTAB matter, or CAFC appeal involving US 5,088,464 was found in the sources checked. With no assertion identified, there is no assignment to test for 6-month pre-suit timing.

6. Bankruptcy fire-sale — NOT PRESENT.

• Echlin's 1998 end was a $3.9B stock-for-stock merger into Dana (reel 011731/0411's assignor lineage), not a bankruptcy sale.
• The 2001 Mr. Gasket carve-out was a strategic divestiture by a solvent Dana (Dana's own Chapter 11 came in 2006 — after the '464 had already moved to Mr. Gasket/PPI), so no bankruptcy estate ever held the '464.
• No Chapter 7/11 sale of the patent appears anywhere in the 1991–2021 record.

7. Privateering — NOT PRESENT.
There is no split between a manufacturing originator and an outsourcing NPE asserting on its behalf. The patent simply rode along inside successive operating performance-parts platforms (Echlin → Mr. Gasket/PPI → Prestolite → ACCEL → Holley group).

8. Defensive aggregator — NOT PRESENT.
The chain does not terminate at RPX, AST, LOT Network, Unified Patents, or OIN. It terminates with ACCEL Performance Group LLC (owner side of the 2015 and 2021 releases; co-obligor on the 2018 liens) inside the Holley family — a commercial brand owner, i.e., the patent was never neutralized by a defensive aggregator.

Verdict

Operating-company assertion — chosen as the closest fit, with one explicit caveat: the "assertion" prong is unmet because no lawsuit was found. Justification: the entire chain from 1991 to 2021 consists of conveyances among operating automotive/performance-parts manufacturers — Meaney's pre-filing assignment to Echlin (reel 005759/0162, 1991-06-05/06-24), the divestiture to Mr. Gasket (reel 011731/0411, 2001), consolidation into Prestolite Wire (reel 019773/0517, 2007), and the current owner-side entity ACCEL Performance Group LLC (named in the 2015 release, reel 036378/0006, and the 2021 releases, reels 058944/0279 and 058948/0926) — and the patent was actually commercialized as the Echlin/ACCEL "Harley-Davidson Thunder Twin Fuel Injection" system under CARB EO D-332-1. No NPE signal is present, and every security-interest recording (2001, 2007, 2018) is a lender lien with a matching release, not an ownership maneuver. Because the assignee still ships products embodying the claims but no competitor suit was located, the more precise characterization is operating-company ownership without evidence of assertion.

Verify (and close the two gaps) at: https://assignmentcenter.uspto.gov/ (search patent number 5088464) and https://assignment.uspto.gov/patent/index.html.

1. Pull the correspondent of record for each reel/frame above to resolve signal #3.
2. Confirm whether reel 027895/0335 (Prestolite Wire LLC → Prestolite Performance LLC, eff. 2011-12-31) covers the '464, since it appears on sibling patents but is missing from this patent's event list.

(Reminder carried from the prior sections: the "General Cable Industries Inc" current-assignee label on the Google Patents landing page conflicts with the recorded chain and likely reflects a Prestolite Wire/General Cable corporate relationship rather than a direct assignment of this patent — treat as uncertain.)

I'll research US 5,088,464 and each of its cited references. Let me run targeted searches.

I have data on the first several references. Let me search the remaining cited references.

Prior‑Art Analysis — US 5,088,464 ("Motorcycle engine management system")

0. Patent identification (confirmed)

The identifier 5088464 resolves to US 5,088,464 A — Motorcycle engine management system, John D. Meaney, filed 1991‑06‑24 (App. 07/720,015), issued 1992‑02‑18, original assignee Echlin, Inc. (source: the authoritative Google Patents record for US5088464A supplied in the prompt). I interpret the number literally; the only numeric distractors (e.g., JP 5088464 B2, a Mitsubishi Materials sputtering‑target patent) are different documents and are not used here.

Minor consistency note: the task header says "Current Date: April 26, 2026," while my operating context says 2026‑09‑29. This does not affect the analysis below, which rests on the patent's own text and citation table.

1. What counts as "the patent citations" here

The '464 patent's own "Patent Citations (9)" table lists nine U.S. patents cited against it (the examiner‑cited reference list). None is a motorcycle patent; all nine are generic automotive internal‑combustion‑engine control references. That fact drives the entire §102 analysis: because both independent claims (1 and 13) are drawn to a motorcycle / V‑twin motorcycle engine management system, no single one of these references discloses every limitation of either independent claim.

All nine predate the '464 filing date (1991‑06‑24) and are therefore available as §102(a)/§102(b)/§102(e) art as applicable. Below, entries marked [verified] were confirmed against the reference's own record in my searches; entries marked [title‑level only] I could not retrieve in full before my search budget was exhausted, so their descriptions are inferred from the title/metadata and should be verified.

2. Reference‑by‑reference analysis

2.1 — US 4,947,816 A (Japan Electronic Control Systems) [verified]

Full citation: US 4,947,816 A; App. US 07/261,887, filed 1988‑10‑25; priority JP 269467 (1987‑10‑27); issued 1990‑08‑14; inventors Nakaniwa Shinpei and Tomisawa Naoki; assignee Japan Electronic Control Systems Co., Ltd.
Description: A fuel‑supply and ignition control system that derives engine driving‑condition parameters (engine speed, engine load, and intake‑air flow‑path area) and computes a fuel supply amount per cylinder from engine speed and an "assumed" engine load (load inferred from intake pressure/throttle). It also derives spark ignition timing and performs air/fuel‑ratio control from the same basic fuel amount, includes altitude‑dependent correction, and adds temporary fuel on an acceleration demand detected from intake‑air‑path‑area variation.
Potential §102 relevance: Its speed + load(intake‑pressure) computation of both fuel quantity and ignition timing maps onto the dual speed/pressure look‑up architecture of claims 1, 2, 13 and 15, and its acceleration enrichment maps onto the acceleration‑enrichment discussion supporting claim 6.
Anticipation conclusion: No whole‑claim §102 anticipation. It is a generic automotive system; it lacks the motorcycle/V‑twin context, the throttle‑body‑mounted injector arrangement, the camshaft pulse 45° BTDC per cylinder, and the N₂O features. Proper basis is §103 (single‑element teaching), not §102.

2.2 — US 4,947,820 A (Toyota) [verified]

Full citation: US 4,947,820 A; priority 1988‑02‑08; issued 1990‑08‑14; assignee Toyota Jidosha K.K.
Description: Determines a basic fuel‑injection time Tp (its flow chart: "STEP 10 — DETERMINE BASIC FUEL INJECTION TIME DURATION Tp") from intake pressure, then multiplies/mods it by an EGR modification factor Fegr and other factors ("Tp = Tp × Fegr," "Tp = Tp × Km + Tv"). It symmetrically computes a basic ignition advance Abase and adds an EGR advance correction.
Potential §102 relevance: This is the closest architectural analogue among the nine to the '464's "base value from a pressure table, then multiply by correction factors" scheme (spec at FIG. 4/5 and the discussion of factors for air temp, oil temp, A/F, WOT, idle, acceleration). Relevant to claims 1, 2 and to the modifier‑type dependent claims (6–12). Its EGR‑on enrichment + ignition modification is also conceptually adjacent to claims 17–19 (enrichment with simultaneous fueling/spark change), though EGR is not "fuel enrichment" and there is no N₂O.
Anticipation conclusion: No whole‑claim §102 anticipation — no motorcycle, no throttle‑body injector, no N₂O, and load is intake‑pressure‑only (no explicit two‑axis speed×pressure map). §103 art.

2.3 — US 4,962,739 A (Mitsubishi Denki) [verified]

Full citation: US 4,962,739 A; priority 1989‑01‑07; issued 1990‑10‑16; assignee Mitsubishi Denki K.K.
Description: Computes in‑cylinder air mass from cylinder pressure at a prescribed piston position during compression plus intake‑air temperature (via a stored conversion‑coefficient look‑up table Cat vs. air temperature and a charging‑correction coefficient Ko vs. speed and air quantity), then computes the injector drive pulse width τ = K1 × 1/K(A/F) × Qa′. Expressly notes "throttle body fuel injection can instead be employed."
Potential §102 relevance: Strong teaching of injector pulse‑width computed from stored look‑up tables and of intake‑air‑temperature compensation — relevant to claim 1 and dependent claim 12. Uses cylinder pressure (not manifold pressure) and does not use a speed×MAP map per se.
Anticipation conclusion: No whole‑claim §102 anticipation (different pressure source, no motorcycle, no throttle‑body injector mounting, no N₂O). §103 art; good secondary reference for the table/A‑I‑temp features.

2.4 — US 4,967,711 A (Fuji Jukogyo) [verified]

Full citation: US 4,967,711 A; priority 1988‑07‑29; issued 1990‑11‑06; assignee Fuji Jukogyo K.K.
Description: Computes intake air quantity Q from a table indexed by engine speed N and cylinder‑pressure change ΔP, then base pulse width Tp = Q/(A/F) for a stoichiometric target. Adds an acceleration correction coefficient K from throttle‑position rate of change ΔTh (with learning), commanding an additional post‑injection Tc = Tp × K. Notably includes a fuel pump 14 and a pressure regulator 15 regulated by intake‑manifold pressure supplying the injectors.
Potential §102 relevance: Relevant to claim 1 (table‑based, speed‑indexed fueling; pump + pressure regulator), claim 6 (throttle‑position‑based modification/acceleration enrichment), and the stoichiometric A/F objective of claim 10. Includes the pump/regulator combination recited in claim 1.
Anticipation conclusion: No whole‑claim §102 anticipation. It lacks the motorcycle context, the throttle‑body‑mounted pair of injectors, the speed×MAP table, and N₂O. §103 art.

2.5 — US 4,967,715 A (Fuji Jukogyo) [title‑level only]

Full citation: US 4,967,715 A; priority 1988‑12‑08; issued 1990‑11‑06; assignee Fuji Jukogyo K.K.
Description (inferred): A sibling of US 4,967,711 from the same assignee/period, "Fuel injection control system for an automotive engine," concerned with determining intake air quantity and injection pulse width from engine operating parameters (cylinder‑pressure/intake parameters), potentially with correction tables. I could not retrieve the full text before exhausting my search budget — treat the description as unverified.
Potential §102 relevance: Expected to be cumulative with 2.4 (claims 1, 6). No whole‑claim anticipation expected.

2.6 — US 4,996,958 A (Mitsubishi Denki) [title‑level only]

Full citation: US 4,996,958 A; priority 1989‑03‑08; issued 1991‑03‑05; assignee Mitsubishi Denki K.K.
Description (inferred): "Ignition timing controlling apparatus for internal combustion engine" — an electronic spark‑timing control reference. Unverified full text.
Potential §102 relevance: Bear principally on the ignition‑angle aspects of claim 2 and claim 15 (second look‑up table for ignition advance). No whole‑claim anticipation of claims 1 or 13.

2.7 — US 5,002,031 A (Mitsubishi Denki) [title‑level only]

Full citation: US 5,002,031 A; priority 1989‑05‑17; issued 1991‑03‑26; assignee Mitsubishi Denki K.K.
Description (inferred): "Fuel control apparatus for an internal‑combustion engine" — fuel injection/quantity control (my search showed it sits in a citation cluster with US 4,947,820 and US 4,881,509, i.e., cylinder‑pressure/intake‑based fuel control). Unverified full text.
Potential §102 relevance: Generic fuel‑control teaching relevant to claim 1. No whole‑claim anticipation.

2.8 — US 5,003,950 A (Toyota) [title‑level only]

Full citation: US 5,003,950 A; priority 1988‑06‑15; issued 1991‑04‑02; assignee Toyota Jidosha K.K.
Description (inferred): "Apparatus for control and intake air amount prediction in an internal combustion engine" — predicting intake air amount for fuel control (i.e., manifold‑pressure/air‑quantity‑based fueling), which is directly on point for the "pressure signal as a function of manifold air pressure" and table‑based fueling of claim 1. Unverified full text.
Potential §102 relevance: Claim 1 (MAP‑based air‑quantity prediction/table addressing). No whole‑claim anticipation.

2.9 — US 5,016,595 A (Toyota) [title‑level only]

Full citation: US 5,016,595 A; priority 1989‑05‑29; issued 1991‑05‑21; assignee Toyota Jidosha K.K.
Description (inferred): "Air‑fuel ratio control device for internal combustion engine" — closed‑loop A/F control, presumably oxygen‑sensor feedback. Unverified full text.
Potential §102 relevance: Bear on claim 10 (oxygen‑sensor feedback to a desired A/F ratio). No whole‑claim anticipation.

3. Anticipation vs. obviousness — bottom line

Applying the correct §102 standard (a single reference must disclose every limitation of the whole claim, arranged as in the claim):

• No cited reference anticipates independent claim 1 or claim 13. Every one of the nine is a generic automotive engine‑control reference. Each is missing at least: (a) the motorcycle / V‑twin motorcycle engine context of the preambles; (b) the throttle body with integrated intake manifold carrying the injector(s) adapted to the motorcycle; (c) for claim 13, the Hall‑effect camshaft sensor producing a pulse at a predetermined angle (45°) BTDC for each cylinder and the double‑fire activation of both injectors on each pulse; and (d) for the nitrous claims (4–5, 16–19), any N₂O source, solenoid and nozzle. Because each dependent claim incorporates all limitations of claim 1 or 13, none of the nine references can anticipate a dependent claim either.
• Accordingly, these nine citations are best characterized as §103 obviousness art for individual elements (base‑fuel/ignition tables indexed by speed and load, correction factors, transient/acceleration enrichment, oxygen‑sensor A/F feedback, temperature compensation, pump + pressure regulator).

Most relevant cited references (ranked):

1. US 4,947,820 (Toyota) — base fuel time from intake pressure modified by factors, plus analogous ignition modification; closest to the '464's table‑plus‑modifier architecture (claims 1, 2; context for 17–19).
2. US 4,947,816 (JECS) — speed + load‑based fuel and spark computation with acceleration enrichment and altitude correction (claims 1, 2, 13, 15; enrichment context).
3. US 4,967,711 (Fuji Jukogyo) — table‑based fueling with pump + intake‑pressure‑regulated pressure regulator, acceleration enrichment, stoichiometric target (claim 1; claim 6; claim 10 context).
4. US 4,962,739 (Mitsubishi) — injector pulse width from look‑up tables with intake‑air‑temperature compensation (claim 1; claim 12).
5. US 5,003,950 (Toyota) — intake‑air‑amount prediction for MAP‑based fueling (claim 1).
6. US 5,016,595 (Toyota) — A/F‑ratio (oxygen‑sensor) control (claim 10).
7. US 4,996,958 (Mitsubishi) — ignition‑timing control (claims 2, 15).
8. US 5,002,031 (Mitsubishi) — generic fuel control (claim 1).
9. US 4,967,715 (Fuji Jukogyo) — cumulative with 2.4 (claims 1, 6).

Also worth flagging (not in the citation list, from the '464 specification itself):

• The assignee's own co‑pending U.S. App. Ser. No. 07/429,789, filed 1989‑10‑26, incorporated by reference — the source of the table‑programming/real‑time‑monitoring teaching. This is the most technically pertinent antecedent art for the '464's programming/table architecture, but it is not one of the nine "Patent Citations" and should not be treated as such.
• The continuation‑in‑part US 5,174,263 A (App. 07/835,609, filed 1992‑02‑13) is the same family, not prior art to the '464.
• The most relevant motorcycle‑specific prior art for the actual claim preambles would be contemporary motorcycle EFI systems, which are absent from the examiner's citation list — a notable gap given the claim preambles.

4. Caveats and verification status

• Verified from primary records during this analysis: US 4,947,816; US 4,947,820; US 4,962,739; US 4,967,711 (and bibliographic confirmation of US 4,967,715 as a same‑assignee sibling).
• Not fully retrieved (title/metadata only): US 4,967,715, US 4,996,958, US 5,002,031, US 5,003,950, US 5,016,595. My searches for these returned only citation‑table snippets or unrelated documents. I was cut off by a tool‑step limit. Their descriptions above are inferred from titles/metadata and must be verified against the references' own front pages/claims before being relied upon. In particular, my §102 conclusions for those five are reasoned from the titles/metadata plus the structure of the '464 claims, not from full‑text review.
• Statutory framing caveat: I have applied the strict whole‑claim §102 test and concluded no anticipation by any single cited reference. If the objective is instead to chart an obviousness (KSR‑style) combination, the mappings above identify which references supply which elements (speed/MAP tables; correction factors; accel enrichment; A/F feedback; temperature compensation; ignition timing), but I have not constructed an element‑by‑element combination chart, and I flag that the motorcycle/V‑twin‑specific and N₂O limitations would still need separate art.
• Dates in the table are the priority and issue (publication) dates reported in the '464 citation table; filing dates can differ (e.g., US 4,947,816's U.S. filing was 1988‑10‑25 with a 1987 JP priority). The record itself notes that some legal‑status/assignee labels on the host page are assumptions, not legal conclusions.
• I did not locate any litigation involving US 5,088,464 in this pass (consistent with the earlier sections, which found none); that is a negative finding from limited sources, not a certification.

If you can supply full‑text exports (or the front pages) for US 4,967,715, 4,996,958, 5,002,031, 5,003,950 and 5,016,595, I can complete the verified descriptions and, if desired, build a formal §103 combination chart against claims 1–19.

I'll ground the analysis by verifying what the cited references actually disclose, since the page gives me only their titles.

Let me verify the remaining cited references.

Obviousness Analysis — U.S. Patent No. 5,088,464 ("Motorcycle engine management system")

0. Sources, scope, and a contradiction check

Contradiction check vs. prior sections: None. The earlier sections established (a) the bibliographic record, (b) the claim structure (19 claims; independent claims 1 and 13), and (c) that no litigation was found. Nothing in this §103 exercise conflicts with those findings. One clarification to carry forward: the "Cited By" / "Similar Documents" entries (e.g., US 5,269,275 Rook, "Pulse width modulated controller for nitrous oxide and fuel delivery," priority 1992‑11‑02; US 5,404,853; US 5,444,627) are later than the '464 filing date (1991‑06‑24) and therefore are not prior art to the '464 patent. They cannot support an invalidity case. The only citable art on the page is the nine examiner‑cited references (all filed 1987–1989, issued Aug. 1990 – May 1991).

Evidentiary limitation: The page provides only titles, dates, and assignees for the nine references. I verified the disclosure content of five of them via search (US 4,967,711; US 5,002,031; US 5,003,950; US 4,996,958; US 5,016,595). For the remaining four (US 4,962,739; US 4,967,715; US 4,947,820; US 4,947,816) I have only the titles and I flag that any limitation built on them must be verified against full text. Where I rely on general knowledge of the art (e.g., batch‑fire injection, injector voltage compensation), I say so explicitly rather than attributing it to a specific reference.

Legal framework: The '464 patent was filed 1991‑06‑24, so it is governed by pre‑AIA 35 U.S.C. §§ 102/103 (Graham v. John Deere; KSR Int'l v. Teleflex, 550 U.S. 398 (2007)). All nine references were filed in 1987–1989 and issued before the '464 application was filed; because each was "granted on an application … filed before the invention by the applicant," each qualifies as §102(e) prior art (subject to the Hilmer doctrine, which is satisfied because their U.S. filing dates all predate 1991), and each is also available as §102(a) art given their issue dates of Aug. 1990 – May 1991 (assuming the invention date is on or after those issue dates, which is likely given the June 1991 filing). Either way, all nine are proper §103 references.

1. Level of ordinary skill (PHOSITA)

A person having ordinary skill in the art as of mid‑1991 would be a mechanical/electrical engineer (or small design team) with 2–4 years' experience in electronic engine control, familiar with speed‑density (MAP/rpm) fuel‑injection strategies, look‑up‑table ("map") based ECUs, distributor/crank‑reference ignition control, and the standard sensor set (MAP, TPS, coolant/air temp, O₂). Motorcycle‑specific experience would be helpful but not required — the field of endeavor is internal‑combustion engine management, and motorcycle and automotive engine control are plainly analogous arts (same field, same problem).

Notably, the specification supplies the PHOSITA definition itself, stating that control algorithms "do not per se form part of the present invention" and that others "are known or can be determined by persons skilled in the art depending upon desired pressure of control and/or the types of available engine sensors." That is a binding admission about the ordinary‑skill level and the predictability of the control logic, and it carries substantial weight under §103.

2. Claim 1 — high invalidity risk

Claim 1 requires, in combination: (a) a throttle body with air‑intake manifold coupled to the engine + operator throttle; (b) ≥1 fuel injector on the throttle body responsive to electronic injector signals; (c) a fuel pump + pressure regulator; (d) an engine‑speed sensor; (e) a manifold pressure sensor; and (f) ECU memory storing injector pulse‑width parameters as a look‑up table indexed by speed and pressure, with means for generating injector control signals from those parameters.

US 5,016,595 (Toyota) alone describes essentially the entire claim 1 architecture — MAP‑based, rpm‑indexed base injection time, corrected by intake‑air temp and O₂ sensor, plus a base ignition table — and US 5,002,031 and US 4,967,711 supply the pump/regulator and throttle‑body details. What remains is the phrase "for a motorcycle engine."

Case for obviousness. Combining these references yields only predictable results (KSR, "predictable use of prior‑art elements according to their established functions"). The motivation is straightforward and multi‑sourced:

• Same field/same problem. Every reference targets the same problem the '464 patent recites in its Background — fuel economy, exhaust emissions, driveability — and the '464 specification concedes the technology existed in automotive form.
• Analogous art. A PHOSITA designing a motorcycle EFI would routinely consult automotive EFI patents; there is no field‑of‑endeavor barrier.
• Market/regulatory pressure. Regulated on‑road motorcycle emissions and fuel‑economy demands supplied a concrete reason to migrate proven automotive EFI technology onto motorcycles.
• The "reason" the art had not been applied is economic, not technical. The specification states electronic control had not been applied to motorcycles "for a number of reasons including … low volume." Low production volume is a market disincentive, not a technical teaching away — and KSR expressly recognizes "market demand" as a permissible motivation. It also undercuts any "long‑felt but unsolved need" narrative.
• Simple substitution. The spec itself frames the claimed hardware as a carburetor replacement, i.e., the substitution of one known fuel‑delivery device for another to obtain its known benefits.
• Self‑admitted conventionality. The "control algorithms … do not per se form part of the present invention" admission removes the principal refuge for claim 1's software/table elements.

Counterargument (patentee). If the preamble "for a motorcycle engine" is treated as limiting and no cited reference suggests a motorcycle application, the patentee may argue the claimed combination is not disclosed. That argument is weak post‑KSR, but it is the only real defense for claim 1. Net: claim 1 is more likely than not obvious over US 5,016,595 in view of US 5,002,031 and/or US 4,967,711.

3. Claims 2, 10–12 — strong obviousness (single added reference)

• Claim 2 (second speed/pressure table for ignition angle): US 5,016,595 expressly stores a "basic ignition timing table" and computes "A BASE"; US 4,996,958 stores "target ignition timing data … [with] the number of rotations and load as parameters" in a ROM and fires the coil from a reference crank position. Motivation: the same ECU and the same two sensors that schedule fuel also schedule spark — a recognized efficiency of integrated engine management. Clearly obvious.
• Claim 10 (O₂ closed loop to desired A/F): US 5,016,595 — O₂ sensor 26 "delivers a signal whose polarity is inverted at the point of a stoichiometric air‑fuel ratio," and the basic injection time "is corrected on the basis of … the O₂ sensor 26." This maps directly onto the '464's stoichiometric‑14.7 correction, including both rich‑and‑lean correction directions. Obvious.
• Claim 11 (engine temperature modifies injection): US 5,016,595 (water‑temperature sensor 28; correction based on water temp) and US 4,967,711 (coolant‑temperature sensor 20, FIG. 2, corrected on the basis of inter‑alia coolant temp). Exchanging coolant temperature for the '464's oil temperature is an obvious design choice (both are engine‑temperature proxies), and the specification offers no unexpected result for oil versus coolant. Obvious.
• Claim 12 (intake‑air temperature modifies injection): US 5,016,595 — intake‑air‑temperature sensor 14, with the basic injection time expressly "corrected on the basis of the outputs of the intake air temperature sensor 14…". Directly obvious.

4. Claims 6–9 — obviousness with mixed strength

• Claim 6 (TPS‑based modification of injection): US 4,967,711 (throttle‑position sensor 19; acceleration‑determining section 27 derives an acceleration correction coefficient from changing throttle opening ΔTh and adds an "additional fuel injection pulse width Tc"); US 5,003,950 (control "on the basis of the amount of throttle opening and the engine speed," including prediction/correction to avoid over‑rich acceleration); US 5,002,031 (throttle opening θ used in control). Obvious.
• Claim 9 (battery‑voltage compensation of injector on‑time): No reference on the page is squarely on point, but injector voltage/dead‑time compensation was routine, well‑known practice in peak‑and‑hold/saturated injector drive as of 1991 (opening time varies with supply voltage). Combined with the specification's admission that such corrections are conventional, this is obvious as a known technique applied for its known purpose, though it warrants a corroborating reference (e.g., an injector‑drive or ECU patent).
• Claims 7 and 8 (operator‑adjustable trim of injection at WOT and at idle, via variable resistors 102/104): These are the least well‑supported claims from the cited art. No cited reference discloses an operator‑adjustable idle/WOT fueling trim. However, the defense is not strong: (i) providing a user‑settable trim to a table‑based ECU is a predictable design choice / adaptation of a known parameterization; (ii) the '464 is expressly an after‑market retrofit targeted at motorcycle owners, so an adjustability incentive is intrinsic to the stated market; and (iii) trim adjustment is the functional equivalent of the correction‑coefficient tables already disclosed in US 4,967,711 and US 5,002,031. Probable obviousness, but these are the claims I would most want a dedicated secondary‑reference search on (e.g., aftermarket "tuner"/potentiometer trim art).

5. Claims 13–15 — the V‑twin/double‑fire claims

Claim 13 adds: (1) a V‑twin engine; (2) a pair of injectors adjacent the cylinder intake ports; (3) a speed sensor producing a pulse at a predetermined angle BTDC for each cylinder; and (4) activation of both injectors on each such pulse.

• Pair of port injectors: US 5,016,595 — "A fuel injection valve 22 for each cylinder projects into the intake manifold 20." Port injection is the standard architecture.
• Per‑cylinder reference pulse at a predetermined angle: US 4,996,958 — rotation sensor 1 detects a reference crank position θ_R, the ignition timing is defined as a crank angle θ_O, and a timer is set from the reference position (the '464's FIG. 7D describes exactly this timer‑from‑edge scheme for both injection and spark). US 5,016,595 uses a pulse train every 30° CA.
• Firing both injectors on every pulse (batch/double fire): This is the simplest known EFI mode — simultaneous/batch injection with a single driver stage. The '464 specification itself presents double‑fire as a cost‑and‑complexity simplification ("Both injectors are turned on or opened at the leading edge of each rpm pulse"), which is precisely the KSR rationale of "use of a known technique to improve … [and] reduce cost." The specific 45° BTDC value is an arbitrary design choice with no asserted criticality.
• The V‑twin/"asymmetric firing" point: The specification expressly disclaims significance — "the characteristic asymmetric timing of Harley‑Davidson engines … is by way of example only, and in no way affects or limits operation of the present invention." That disclaimer removes the strongest candidate for a non‑obviousness argument built on V‑twin peculiarity (and it also rebuts any "teaching away because of vibration/asymmetric firing" theory).
• Claim 14 (supplemental sensor modifies base time): US 5,016,595 / US 4,967,711 corrections — obvious. Claim 15 (ignition table + double‑fire spark): US 4,996,958 + US 5,016,595 — obvious.

Net: claims 13–15 are obvious over US 5,016,595 in view of US 4,996,958 and US 4,967,711.

6. Claims 3–5 and 16–19 — the nitrous‑dependent claims (weakest invalidity case on this record)

These claims introduce (i) a source of fuel enrichment with a valve mounted on the throttle body (claim 3/16), (ii) N₂O under pressure as that source (claim 4), (iii) automatic increased injection upon enrichment (claims 5/17/19), and (iv) automatic spark retard upon enrichment (claims 18/19).

On the art cited by the examiner, this is the soft spot. None of the nine references discloses nitrous‑oxide enrichment, and the natural nitrous reference — US 5,269,275 (Rook), which appears on the page under "Cited By" — has a 1992 priority date and is not prior art to the '464. So the examiner's cited art alone does not dispose of claim 4, and does not directly supply claims 16–19's nitrous‑triggered fuel/spark responses.

That said, the invalidity case can still be made with non‑patent prior art, and the patentee's own specification weakens the position:

• Claim 3's generic "source of fuel enrichment" (without N₂O) reads on conventional cold‑start/power‑enrichment valves and auxiliary enrichment injectors mounted in the intake manifold, which were ubiquitous. If claim 3 is construed to cover any controlled supplemental‑fuel valve on the throttle body, it is obvious over US 4,967,711's acceleration‑enrichment teaching (additional fuel injected on acceleration demand, via the same driver).
• Claim 5's "automatically … increase fuel injection when fuel enrichment is delivered" is simply holding a target A/F ratio when a new fuel/oxidizer source is added — the same control problem US 5,016,595 and US 4,967,711 already solve via correction factors. Obvious.
• Claim 18's "automatically retard ignition when fuel enrichment is delivered" is supported in principle by US 4,947,820 (Toyota, "Combustion control system … adaptable to on and off of exhaust gas recirculation"), which switches combustion/ignition control parameters based on a change in the charge‑forming condition. Substituting N₂O for EGR as the charge‑affecting condition, with retard to avoid knock, is a predictable design choice once a nitrous system is assumed. (This is a title‑only reference here — verify full text.)
• Claim 4's N₂O container is the narrowest claim, and the specification's treatment of nitrous hardware as conventional ("an orifice size of 0.010 inches roughly equates with an increase in available horsepower of about 20 horsepower") supports the view that nitrous injection kits were known and routine, needing only documentation (e.g., pre‑1991 aftermarket N₂O system literature or a patent) to complete a §103 combination.

Assessment: claims 4, 16, 17, 18, 19 are the only claims with a realistic survival argument on the present record, and their validity depends almost entirely on whether pre‑1991 nitrous‑for‑motorcycle prior art can be located. If it can, these claims fall too; if not, they survive (though claim 4 would then be a narrow species claim of limited commercial effect, since it is dependent).

7. Summary claim chart

8. Secondary considerations (objective indicia)

• Commercial success: The earlier sections noted CARB Executive Order D‑332‑1 (1995‑05‑25) for the Echlin/ACCEL "Harley‑Davidson Thunder Twin Fuel Injection" kit. This is real evidence of market acceptance, but nexus is weak: the success is plausibly attributable to brand (ACCEL/Echlin), dealer distribution, and the Harley cruiser aftermarket rather than to any single claimed feature — especially since claims 1–15 are combinations of admittedly conventional elements. Under the Federal Circuit's nexus line of cases, this limits the probative weight.
• Long‑felt need: Cut against the patentee — the specification attributes non‑adoption to "low volume" (economic), not to any unsolved technical obstacle. KSR treats market demand as a motivation to combine, not as evidence of non‑obviousness.
• Unexpected results: The asserted "15% horsepower increase between 5,000 and 6,000 rpm" is measured against the original carbureted baseline, not against the closest prior art (automotive EFI systems). Gaining power and driveability by replacing a carburetor with mapped EFI is the expected result; absent a showing that the gain exceeds what the art predicts, this factor carries little weight.
• Teaching away: None found. If anything, the specification's own disclaimer that Harley‑Davidson asymmetric firing "in no way affects or limits" the invention eliminates the best candidate for a teaching‑away argument.

9. Bottom line and recommended verification

1. Claims 1, 2, 6, 10, 11, 12, 13, 14, and 15 are, in my assessment, more likely than not invalid under §103 over US 5,016,595 (Toyota) in view of US 5,002,031 (Mitsubishi), US 4,967,711 (Fuji), and US 4,996,958 (Mitsubishi). The motivations are the classic KSR rationales: same field/same problem, analogous art, predictable substitution of a known fuel‑delivery/control architecture, market/regulatory demand, and cost reduction (the specification's own emphasis on batch double‑fire).
2. Claims 7, 8, and 9 are probably obvious but are not fully supported by the nine cited references; they need either a secondary reference (trim/potentiometer engine tuning; injector voltage compensation) or reliance on the "known technique" rationale.
3. Claims 4, 16, 17, 18, and 19 (nitrous) cannot be invalidated on the examiner's cited art alone. The obvious nitrous reference on the page — US 5,269,275 (Rook) — is later than the '464 filing date and is therefore not prior art. These claims would require documentation of pre‑June‑1991 nitrous‑oxide enrichment systems (aftermarket kit literature, CARB/EPA filings, or an earlier N₂O patent), plus US 4,947,820 for the "retard‑on‑condition‑change" concept.

Caveats I want to state plainly: (a) I have verified full or abstract disclosure content for only five of the nine cited references; conclusions resting on US 4,962,739, US 4,967,715, US 4,947,820, and US 4,947,816 rest on their titles and must be confirmed. (b) Claim construction of the preambles ("for a motorcycle engine," "for a V‑twin motorcycle engine") materially affects the claim 1/13 analysis; I have assumed they are limiting, which is the construction most favorable to the patentee, and the claims still fail. (c) Whether US 5,016,595 discloses a fuel pump and pressure regulator in its express description should be confirmed from its full text; if not, that element is supplied by US 4,967,711, which expressly does. (d) For a filing‑grade conclusion, obtain the full PDFs of the nine references from USPTO Patent Center/Google Patents (e.g., https://patents.google.com/patent/US4967711, https://patents.google.com/patent/[US5002031A](/patent/US5002031A)/en, https://patents.google.com/patent/[US4996958A](/patent/US4996958A)/en, https://patents.google.com/patent/[US5016595A](/patent/US5016595A)/en, https://patents.google.com/patent/US5003950) and run a dedicated search for pre‑1991 motorcycle nitrous‑injection art.