Yamaha 1996 9.9 HP Outboard Specs & Maintenance
Looking to keep your 1996 9.9 HP two-stroke outboard running like new? Featuring a lightweight 2-cylinder, 246cc (15 cu in) inline engine, this classic motor is a favorite among anglers and skiff owners for its bulletproof reliability and punchy power-to-weight ratio. Whether you’re troubleshooting a rough idle or performing a seasonal tune-up, our database provides the essential specs, spark plug gaps, and practical advice every DIY marine mechanic needs to master this legendary workhorse.
Complete Technical Specifications
| Specification | Details |
|---|---|
| Model / Horsepower | 9.9 |
| Year Range | 1996 |
| Engine Type | IL 2-stroke |
| Cylinders | 2 |
| Displacement | 15 cu-in (246 cc) |
| Bore x Stroke | 2.20 x 1.97 in (56 x 50 mm) |
| Compression Ratio | 6.8:1 |
| Full Throttle RPM | 4500-5500 |
| Idle Speed (Neutral) RPM | 700-800 |
| Idle Speed (Trolling) RPM | 600-700 |
| 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 |
| Ignition Timing (Carb Pickup) | — |
| Ignition Timing (Full Advance) | 29-31 |
| Fuel System | Carb |
| Starting System | Man or Man & Elec |
| Oil Injection System | Pre-Mix 100:1 |
| Injection Oil Ratio | Pre-Mix 100:1 |
| Gear Oil Capacity (mL/cc) | 185 |
| Gear Oil Capacity (Oz) | 6.3 |
| Approximate Weight | 80-90 lbs (36-41 kg) |
| Battery CCA / Reserve | 210 (40) |
| Battery Reserve | 59 minutes |
| Tach Pole Setting | 5 |
| Test Propeller Part Number | YB-1619 |
| Test Propeller New Engine RPM | 5000-5200 |
Maintenance Summary
Routine maintenance is simple for this 246cc twin-cylinder. Keep the ignition firing hot with NGK B7HS-10 spark plugs gapped to 0.035–0.039 in (0.9–1.0 mm). Always mix fresh 2-stroke oil, inspect the water pump impeller annually, and service lower unit lube to ensure peak performance on the water.
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Notice: Specifications, fuel ratios, and maintenance guidelines listed on VintageMotorSpecs.com are compiled for historical reference and educational purposes only.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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