Two Stroke
50 H.P.
50 HP stock
50:1 mix
it is a 485cc fan-cooled 2-stroke engine.
The correct ratio for 1991 85hp Yamaha is 1:50. 1 liter of oil for 50 liters of fuel.
For a 1991 Yamaha YZ 125, the recommended gas-oil mixture is typically a ratio of 32:1, which means 4 ounces of 2-stroke oil per gallon of gasoline. It's important to use high-quality, JASO FC or ISO EGD rated 2-stroke oil to ensure proper lubrication and engine performance. Always refer to the owner's manual for the most accurate specifications and recommendations.
no drainplug on the engine. fan-cooled 2-stroke. it has no dedicated oil sump. to drain the chaincase oil just remove the cover, wipe out all the oil, re-install chaincase cover and fill with new oil.
The length of a 1991 WaveRunner model can vary depending on the specific model and manufacturer. However, on average, WaveRunners from that era typically ranged in length from 7 to 10 feet. For the exact length of a specific 1991 WaveRunner model, you would need to refer to the manufacturer's specifications.
32:1 is standard fuel mixture for 2 stroke engines, you can use different ratios but this is the reccomended ratio by the manufacturer.
The dry weight of a 1991 model, 130 hp Yamaha outboard is 357lbs.
1991
bore 3.497 stroke 3.81