Yamaha 1987-88 28J HP Outboard Specs & Maintenance
Known for its bulletproof reliability and smooth power delivery, the 1987-1988 28J HP outboard motor remains a favorite among vintage marine enthusiasts. Packing a punch with its 3-cylinder, 43 cubic inch (698cc) inline 2-stroke design, this engine offers exceptional torque for light commercial and recreational craft alike. Whether you are performing a seasonal overhaul or routine maintenance, our technical database provides the precise specs you need to keep this classic running strong.
Complete Technical Specifications
| Specification | Details |
|---|---|
| Model / Horsepower | 28J |
| Year Range | 1987-88 |
| 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) | 0-2 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
Keeping your 28J in peak condition requires basic 2-stroke care. Always run fresh fuel mixed with quality marine oil, service the water pump impeller annually, and inspect the lower unit gear lube. For optimal ignition, install fresh NGK B7HS-10 spark plugs gapped to 0.035-0.039 inches (0.9-1.0 mm).
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Notice: Specifications, fuel ratios, and maintenance guidelines listed on VintageMotorSpecs.com are compiled for historical reference and educational purposes only.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.
Spot an error or discrepancy in these specs? Please contact us with your engine details so we can update our database.
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