Yamaha 1995-96 4 HP Outboard Specs & Maintenance
Keep your 1995-1996 4 HP 2-stroke outboard running like new with our comprehensive technical database. Featuring a reliable 6.3 cu in (103 cc) single-cylinder design, this lightweight motor is a favorite among DIY mechanics for powering dinghies and skiffs. Whether you’re performing routine service or a complete overhaul, explore our original factory specs and maintenance tips to keep this classic marine engine pushing water for years to come.
Complete Technical Specifications
| Specification | Details |
|---|---|
| Model / Horsepower | 4 |
| Year Range | 1995-96 |
| Engine Type | CL 2-stroke |
| Cylinders | 1 |
| Displacement | 6.3 cu-in (103 cc) |
| Bore x Stroke | 2.13 x 1.77 in (54 x 45 mm) |
| Compression Ratio | 6.5:1 |
| Full Throttle RPM | 4500-5500 |
| Idle Speed (Neutral) RPM | 1100-1200 |
| Idle Speed (Trolling) RPM | 950-1050 |
| Spark Plug (NGK) | B7HS |
| Spark Plug (Champion) | L82C |
| Spark Plug Gap | 0.024-0.028 in (0.6-0.7 mm) |
| Ignition System | CDI |
| Ignition Timing (Idle) | 3-9 |
| Ignition Timing (Carb Pickup) | — |
| Ignition Timing (Full Advance) | 25-31 |
| 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) | 105 |
| Gear Oil Capacity (Oz) | 3.6 |
| Approximate Weight | 46-47 lbs (21-22 kg) |
| Battery CCA / Reserve | n/a |
| Battery Reserve | n/a |
| Tach Pole Setting | 4 |
| Test Propeller Part Number | YB-1630 |
| Test Propeller New Engine RPM | 4500-5500 |
Maintenance Summary
Proper maintenance for this single-cylinder powerhead hinges on fresh fuel-oil mixes and a strong spark. Keep your motor starting effortlessly by installing an NGK B7HS spark plug gapped precisely to 0.024–0.028 inches (0.6–0.7 mm). Regularly check the water pump impeller to prevent overheating.
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Notice: Specifications, fuel ratios, and maintenance guidelines listed on VintageMotorSpecs.com are compiled for historical reference and educational purposes only.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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