Yamaha 1988-96 3 HP Outboard Specs & Maintenance
Lightweight, reliable, and surprisingly punchy, the 1988-1996 3 HP single-cylinder 2-stroke outboard remains a favorite for dinghies, tenders, and small fishing boats. Featuring a compact 4.3 cu. in. (70 cc) displacement, this ultra-portable engine delivers uncomplicated, dependable performance on the water. Whether you are restoring a classic back-up motor or maintaining your weekend runner, our database provides the technical specs and repair guidance DIY mechanics need to keep it running strong.
Complete Technical Specifications
| Specification | Details |
|---|---|
| Model / Horsepower | 3 |
| Year Range | 1988-96 |
| Engine Type | IL 2-stroke |
| Cylinders | 1 |
| Displacement | 4.3 cu-in (70 cc) |
| Bore x Stroke | 1.81 x 1.65 in (46 x 42 mm) |
| Compression Ratio | 6.9:1 |
| Full Throttle RPM | 4500-5500 |
| Idle Speed (Neutral) RPM | 1150-1250 |
| Idle Speed (Trolling) RPM | 1000-1100 |
| Spark Plug (NGK) | B6HS-10 |
| Spark Plug (Champion) | L86C |
| Spark Plug Gap | 0.035-0.039 in (0.9-1.0 mm) |
| Ignition System | CDI |
| Ignition Timing (Idle) | 4-8 |
| Ignition Timing (Carb Pickup) | — |
| Ignition Timing (Full Advance) | 18-24 |
| Fuel System | Carb |
| Starting System | Manual |
| Oil Injection System | Pre-Mix 100:1 |
| Injection Oil Ratio | Pre-Mix 100:1 |
| Gear Oil Capacity (mL/cc) | 75 |
| Gear Oil Capacity (Oz) | 2.5 |
| Approximate Weight | 36-39 lbs (16.5-17.5 kg) |
| Battery CCA / Reserve | n/a |
| Battery Reserve | n/a |
| Tach Pole Setting | — |
| Test Propeller Part Number | YB-1630 |
| Test Propeller New Engine RPM | 4500-5500 |
Maintenance Summary
Keeping this 70 cc powerhead reliable requires simple, routine care. Always run fresh, properly mixed 2-stroke fuel and maintain hot spark ignition by gapping a fresh NGK B6HS-10 plug to 0.035–0.039 inches (0.9–1.0 mm). Regular lower-unit gear oil changes will keep this lightweight engine running smoothly.
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Notice: Specifications, fuel ratios, and maintenance guidelines listed on VintageMotorSpecs.com are compiled for historical reference and educational purposes only.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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