Regular gasoline. If you trailer the boat, stop at a gas station on the way to the launch and fuel, for two reasons: it's less expensive than at a marina, and it'll give the gas vapors time to dissipate before you launch.
Premium gasoline
The fuel mixture for a Yamaha 40 hp 2 stroke outboard engine is 50:1, gas, oil mixture. You should use new gas when you get the engine ready for the season.
it is a 4 stroke so unleaded.
5w-30
4 stroke
2 stroke-NOT outboard, but the same type such as used in chainsaws
A 2.5 Mercury outboard motor typically uses a mixture of unleaded gasoline and two-stroke engine oil, usually in a 50:1 ratio. It's essential to use a high-quality oil specifically designed for two-stroke engines to ensure optimal performance and engine longevity. Always check the owner's manual for specific fuel recommendations and mixing instructions.
The 1976 model, 115 hp Mercury outboard, requires a 50:1 fuel to 2 cycle oil ratio. This is roughly one pint of 2 cycle oil, to six gallons of fuel. The use of 4 stroke type motor oil is not recommended, nor intended, for fuel / oil mix.
I use 80 weight gear oil.
Type your answer here... a diagram of a honda 2003 recon fuel line
four stroke motorcycle oil .
Most outboard manufacturers recommend a good quality 10W-30 motor oil for use in colder climates.