Yamaha 1989-96 85 HP Outboard Specs & Maintenance
Built between 1989 and 1996, the 85 HP inline 3-cylinder 2-stroke outboard is a mid-range powerhouse renowned for its impressive power-to-weight ratio and bulletproof reliability. Boasting a robust 70 cubic inch (1140 cc) displacement, this triple-cylinder motor remains a favorite among DIY boaters looking to keep classic hulls cruising. Whether you are troubleshooting ignition issues or performing seasonal tune-ups, our technical database provides the exact specs you need to keep your engine running smooth.
Complete Technical Specifications
| Specification | Details |
|---|---|
| Model / Horsepower | 85 |
| Year Range | 1989-96 |
| Engine Type | IL 2-stroke |
| Cylinders | 3 |
| Displacement | 70 cu-in (1140 cc) |
| Bore x Stroke | 3.23 x 2.83 in (82 x 72 mm) |
| Compression Ratio | 5.2:1 |
| Full Throttle RPM | 4500-5500 |
| Idle Speed (Neutral) RPM | 750-850 |
| Idle Speed (Trolling) RPM | 550-650 |
| Spark Plug (NGK) | B8HS-10 |
| Spark Plug (Champion) | L78C |
| Spark Plug Gap | 0.035-0.039 in (0.9-1.0 mm) |
| Ignition System | CDI Micro |
| Ignition Timing (Idle) | 6-8 ATDC |
| Ignition Timing (Carb Pickup) | 6-8 ATDC |
| Ignition Timing (Full Advance) | 23-25 |
| Fuel System | Carb |
| Starting System | Electric |
| Oil Injection System | Pre-Mix 50-1 |
| Injection Oil Ratio | Pre-Mix 50:1 |
| Gear Oil Capacity (mL/cc) | 610 |
| Gear Oil Capacity (Oz) | 20.6 |
| Approximate Weight | 248-255 lbs (113-116 kg) |
| Battery CCA / Reserve | 380 (70) |
| Battery Reserve | 124 minutes |
| Tach Pole Setting | 12 |
| Test Propeller Part Number | YB-1620 |
| Test Propeller New Engine RPM | 5100-5300 |
Maintenance Summary
Routine maintenance is key to preserving this 3-cylinder’s two-stroke punch. For optimal combustion and reliable starts, install fresh NGK B8HS-10 spark plugs gapped precisely to 0.035–0.039 inches (0.9–1.0 mm). Always verify fuel-to-oil ratios and inspect the impeller annually to protect your engine investment.
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Notice: Specifications, fuel ratios, and maintenance guidelines listed on VintageMotorSpecs.com are compiled for historical reference and educational purposes only.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.
Non-Affiliation Notice: VintageMotorSpecs.com is an independent historical reference database and is not affiliated, associated, authorized, endorsed by, or in any way officially connected with Outboard Marine Corporation (OMC), Mercury Marine, Yamaha, Honda, or any of their subsidiaries or affiliates. All product names, trademarks, and registered trademarks are property of their respective owners.