Yamaha 1993-95 9.9 HP Outboard Specs & Maintenance
Built between 1993 and 1995, this 9.9 HP 2-cylinder, 2-stroke outboard remains a legendary choice for tenders and fishing boats alike. Packing a punch with its 15 cu in (246 cc) displacement, this lightweight workhorse delivers exceptional power-to-weight reliability. Whether you’re restoring a classic or keeping a daily runner in top shape, our technical specs and service guides will help you tackle any DIY maintenance project with confidence.
Complete Technical Specifications
| Specification | Details |
|---|---|
| Model / Horsepower | 9.9 |
| Year Range | 1993-95 |
| 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 | 850-950 |
| Idle Speed (Trolling) RPM | 700-800 |
| 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) | 9-11 |
| 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 | 4 |
| Test Propeller Part Number | YB-1619 |
| Test Propeller New Engine RPM | 5000-5200 |
Maintenance Summary
Routine tune-ups keep this twin-cylinder 2-stroke firing effortlessly. For clean combustion and steady idling, inspect and replace your spark plugs with NGK B7HS-10 units gapped to 0.035–0.039 inches (0.9–1.0 mm). Combine fresh plugs with properly mixed fuel and seasonal gearcase lube service for long-lasting performance.
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Notice: Specifications, fuel ratios, and maintenance guidelines listed on VintageMotorSpecs.com are compiled for historical reference and educational purposes only.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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