816761Q17 Aftermarket Mercruiser V8 CDI Thunderbolt/Delco HEI Ignition Cable Kit (1987-2003) | Sawley's Select Marine Parts

🔧 Product Description

Aftermarket replacement Small-Block V8 Distributor Ignition Lead Set - Replaces Part Number: 816761Q17

New nine-lead ignition-cable set replacing MerCruiser 816761Q17 for GM 305/350 CID small-block V8 engines with Thunderbolt IV/V or specified Delco HEI distributor ignition.

⚙️ Key Features

• Nine-lead V8 distributor set

• Supports 5.0L/305 and 5.7L/350 engines

• Marine suppression cable and heat-resistant boots

• Suitable for Thunderbolt IV/V and specified Delco distributors

• Includes eight plug leads and one coil lead

🧰 Kit / Assembly Contents

• 8 × Spark-plug leads - serviced only as kit P/N 816761Q17

• 1 × Distributor-to-ignition-coil lead - serviced only as kit P/N 816761Q17

🔄 Supersession & Cross Reference

OEM Supersession Chain:

• 816761Q17 → Supersedes/updates 816761A17

• 816761A17 → Related to 816761A4/Q3/Q4 and 813720A3/A4

OEM / Related Numbers:

• 816761A17

• 816761A4

• 816761Q3

• 816761Q4

• 813720A3

• 813720A4

Aftermarket / Verified Equivalents:

• CDI Electronics: 631-0004

• Sierra small-block V8 marine lead-set family matched by routing

• Mallory: 9-28003 / 9-28030

• Recmar: REC816761Q17

🚤 Compatibility

Commonly used on:

• MerCruiser GM small-block V8 distributor ignition engines

Typically suits:

• Engine / Equipment models:

• 5.0L/305 V8

• 5.7L/350 V8

• Thunderbolt IV/V and specified Delco HEI applications

• HP / Output Range: Approximately 198HP - 300HP

• Engine / System Type: GM small-block V8 petrol marine engine with distributor ignition

• Year Range: Approximately 1987 - 2003; serial-dependent

• Serial / Component Identification: Confirm straight/angled boot layout; ECM555 flat-cap MPI engines use a different wire set.

🔌 Function

The ignition leads carry high-voltage energy from the distributor or individual coils to the spark plugs. Marine-grade insulation and correctly fitted terminals prevent leakage, crossfire and radio-frequency interference.

Common signs of failure / service requirement:

• Misfire under acceleration or high load

• Visible arcing in darkness or around damp lead boots

• Cracked, hardened or oil-contaminated insulation

• Excessive lead resistance or open circuit

• Rough idle, crossfire or radio-frequency interference

📦 Condition

• New aftermarket replacement part

• Brand new

• Supplied in original or equivalent packaging