Yamaha 1984-86 30 HP Outboard Specs & Maintenance
Built between 1984 and 1986, this 30 HP two-cylinder, two-stroke outboard remains a reliable workhorse for small craft and skiffs. Packing a punch with its 30 cubic inch (496 cc) displacement, this in-line twin delivers dependable power and mechanical simplicity. Whether you are restoring a classic hull or keeping a vintage daily runner in top shape, our database provides the essential technical specs and repair insights DIY mechanics need to keep this motor purring.
Complete Technical Specifications
| Specification | Details |
|---|---|
| Model / Horsepower | 30 |
| Year Range | 1984-86 |
| Engine Type | IL 2-stroke |
| Cylinders | 2 |
| Displacement | 30 cu-in (496 cc) |
| Bore x Stroke | 2.83 x 2.40 in (72 x 61 mm) |
| Compression Ratio | 7.0:1 |
| Full Throttle RPM | 4500-5500 |
| Idle Speed (Neutral) RPM | 850-950 |
| Idle Speed (Trolling) RPM | 750-850 |
| Spark Plug (NGK) | B7HS |
| Spark Plug (Champion) | L82C |
| Spark Plug Gap | 0.020-0.24 in (0.5-0.6 mm) |
| Ignition System | CDI |
| Ignition Timing (Idle) | — |
| Ignition Timing (Carb Pickup) | — |
| Ignition Timing (Full Advance) | 24-26 |
| 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) | 180 |
| Gear Oil Capacity (Oz) | 6.1 |
| Approximate Weight | 107-120 lbs (49-55 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 | 5000-5200 |
Maintenance Summary
Keep your 1984–86 30 HP running smoothly with routine ignition and fuel maintenance. For peak performance, inspect and replace ignition components using NGK B7HS spark plugs gapped to 0.020–0.024 inches (0.5–0.6 mm). Regular decarbonization and proper fuel mixing will ensure reliable, long-term operation 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Notice: Specifications, fuel ratios, and maintenance guidelines listed on VintageMotorSpecs.com are compiled for historical reference and educational purposes only.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.
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.