Yamaha 1989-94 28J HP Outboard Specs & Maintenance
The 1989-1994 28J HP outboard motor is a workhorse among late-80s and early-90s mid-range marine engines. Featuring a smooth-running 3-cylinder inline 2-stroke design with a 43 cu in (698 cc) displacement, this reliable powerplant offers excellent hole-shot performance for smaller craft. Whether you’re restoring a classic rig or performing routine tune-ups, our guide provides the exact specs DIY mechanics need to keep it running strong.
Complete Technical Specifications
| Specification | Details |
|---|---|
| Model / Horsepower | 28J |
| Year Range | 1989-94 |
| Engine Type | IL 2-stroke |
| Cylinders | 3 |
| Displacement | 43 cu-in (698 cc) |
| Bore x Stroke | 2.64 x 2.60 in (67 x 66 mm) |
| Compression Ratio | 6.0:1 |
| Full Throttle RPM | 4500-5500 |
| Idle Speed (Neutral) RPM | 750-850 |
| Idle Speed (Trolling) RPM | — |
| Spark Plug (NGK) | B7HS-10 |
| Spark Plug (Champion) | L82C |
| Spark Plug Gap | 0.035-0.039 in (0.9-1.0 mm) |
| Ignition System | CDI |
| Ignition Timing (Idle) | 4-6 ATDC |
| Ignition Timing (Carb Pickup) | 4-6 ATDC |
| Ignition Timing (Full Advance) | 24-26 |
| Fuel System | Carb |
| Starting System | Manual and/or Elec |
| Oil Injection System | Precision Blend |
| Injection Oil Ratio | Precision Blend |
| Gear Oil Capacity (mL/cc) | n/a |
| Gear Oil Capacity (Oz) | n/a |
| Approximate Weight | 158 lbs (72 kg) |
| Battery CCA / Reserve | 210 (40) |
| Battery Reserve | 59 minutes |
| Tach Pole Setting | 6 |
| Test Propeller Part Number | — |
| Test Propeller New Engine RPM | — |
Maintenance Summary
Keep your 28J running at peak efficiency by replacing spark plugs regularly. This 3-cylinder engine requires NGK B7HS-10 plugs, gapped precisely between 0.035 and 0.039 inches (0.9-1.0 mm). Always inspect lower unit gear lube and maintain fresh 2-stroke fuel to protect its 698cc powerhead.
Disclaimer & Information Notice: Specifications, fuel ratios, and maintenance guidelines listed on VintageMotorSpecs.com are compiled for historical reference and educational purposes only. Always verify data against an official OEM service manual prior to ordering parts or executing repairs. VintageMotorSpecs.com assumes no liability for repair errors, equipment damage, or personal injury resulting from the use of this data.
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