i need help with my 2 stroke yamaha outboard

[chazwaza]

hi , im charlie

i need to know what ratio of oil to petrol i need to use in my yamaha 2 stroke 15hp outboard engine please help me

[Alan Power]

Wat year?

[tom28571]

All 2 stroke Yamahas that I have used need 100:1 fuel oil ratio. I find that it pays to also add a little of a product they call Ring Free to the mix. The very lean ratio can cause piston rings to freeze up.

[steigermike]

tom is right and the ring free is good advice, also if your premixing its best to be a little over than under.

[FAST FRED]

Be aware that the bigest reason for DEAD outboards is old premix gas.

ONLY mix enough for the day or weekend , and when finished , pour the mix into what ever gas auto you have.

The octane rating of gas declines rapidly with the addition of oil , and many outboards NEED good octane to survive.

Most new cars have detonation sensors so can eat last weeks gas with no prpblem.

Also be aware that there are many types of 2 stroke oil ,
ONLY use the stuff made for outboards, any brand is OK .

FAST FRED

[Mick Folan]

Following on from that i have a two stroke 15 hp mariner as an auxillary for my Perkins 4108 how long would the petrol last if i didnt add the oil mix.

[Alan Power]

Originally Posted by Mick Folan

Following on from that i have a two stroke 15 hp mariner as an auxillary for my Perkins 4108 how long would the petrol last if i didnt add the oil mix.

The petrol would last a lot longer than your engine with no oil

[gonzo]

The problem with old mix is separation. Two stroke petroleum based oils have zinc as an additive. After a couple of months it sediments. That is what causes that jelly looking stuff. It will clog the fuel pump and the oil injection orifices. A syntetic oil prevents that. It is not a suspension but a complete solution.