Oil To Gas Ratio for 25HP 77 Evinrude

[JoeBar303]

I just bought a 12' fiberglass boat with an old 1977 25HP evinrude outboard motor on it not too long ago. We took it out and it ran horribly because of old gas. I don't know the gas to oil ratio so I can't mix up some fresh fuel. I kind of think it might be 50:1 but I'm not sure. Can anyone help me? <br /><br />Thank You.

 

[bubbakat]

Re: Oil To Gas Ratio for 25HP 77 Evinrude

50:1 would be the correct ratio<br />87 octane will do fine in that engine.

 

[timmathis]

Re: Oil To Gas Ratio for 25HP 77 Evinrude

40:1 would be ok 50:1 could be better!

 

[bubbakat]

Re: Oil To Gas Ratio for 25HP 77 Evinrude

What makes you think 40:1 would be ok.<br />The manufacturer of that motor said use 50:1 so why go against what the motor was designed to take?

 

[jurgenscraft]

Re: Oil To Gas Ratio for 25HP 77 Evinrude

50 : 1 is the correct ratio too much oil = plugs will foul up, too little oil = engine will blow up.<br />Kind regards William Wright

 

[JoeBar303]

Re: Oil To Gas Ratio for 25HP 77 Evinrude

Thanks alot for the help. I'll mix up a new batch of fuel for the weekend. Hopefully it will be a smoother ride. Thanks again, Joe Bartley.