Yamaha 1996 20 HP Outboard Specs & Maintenance
Looking to keep your 1996 20 HP 2-stroke outboard running like new? This reliable twin-cylinder, 395cc (24 cu. in.) workhorse is a favorite among DIY boat mechanics for its lightweight punch and straightforward design. Whether you’re troubleshooting ignition issues, sourcing parts, or performing routine tune-ups, our comprehensive technical database provides the exact specs and service details you need to keep your vintage marine engine performing reliably on the water.
Complete Technical Specifications
| Specification | Details |
|---|---|
| Model / Horsepower | 20 |
| Year Range | 1996 |
| Engine Type | IL 2-stroke |
| Cylinders | 2 |
| Displacement | 24 cu-in (395 cc) |
| Bore x Stroke | 2.64 x 2.20 in (67 x 56 mm) |
| Compression Ratio | 7.2:1 |
| Full Throttle RPM | 5000-6000 |
| 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) | 6-8 ATDC |
| Ignition Timing (Carb Pickup) | 0-1 ATDC |
| Ignition Timing (Full Advance) | 24-26 |
| Fuel System | Carb |
| Starting System | Man or Man & Elec |
| Oil Injection System | PB or 100:1 PM |
| Injection Oil Ratio | PB or 100:1 PM |
| Gear Oil Capacity (mL/cc) | 370 |
| Gear Oil Capacity (Oz) | 12.5 |
| Approximate Weight | 106-117 lbs (48-53 kg) |
| Battery CCA / Reserve | 210 (40) |
| Battery Reserve | 59 minutes |
| Tach Pole Setting | 4 |
| Test Propeller Part Number | YB-1621 |
| Test Propeller New Engine RPM | 4200-4400 |
Maintenance Summary
Keep this 24 cu. in. twin-cylinder engine performing smoothly with regular ignition care. Install fresh NGK B7HS-10 spark plugs gapped precisely to 0.035–0.039 inches (0.9–1.0 mm). Always mix fresh 2-stroke fuel, check lower unit lube annually, and inspect water pump impellers 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Notice: Specifications, fuel ratios, and maintenance guidelines listed on VintageMotorSpecs.com are compiled for historical reference and educational purposes only.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.
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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