2 stroke oil in a four stroke engine sump

[yebaws]

Oops...When changing the oil for my four stroke outboard I accidentally filled it up with 2 stroke oil. Realised my mistake before starting up and have now drained it again. Will this be OK if I now fill up with fresh oil or should I try and clean every last drop of the 2 stroke out (and if so how?)

Thanks.

[ShinyShoe]

If you really wanted to clean it out you can get engine oil flushes. (Although some at least need you to run up the engine!). I gather they thin the old oil to make it come out and have some detergents to help too...

2 stroke is runnier than 4 stroke so I think it will actually run out easier than the 4S, presumably bringing some old 4S residues with it. You might want to measure what comes out and compare to what you put in.?

If in doubt get some cheap 4S oil, replace the 2S with cheap, run it gently on the cheap for a few minutes and then re-replace with your finest brand of 4S. You'd presumably see the blue colour in the oil? Assumign your 2S is blue like mine...?

[ShinyShoe]

Oh and make sure you have a new plug when you go out - just incase you carbon up the old one ;-)

[camelgas]

I would flush the motor with cheap oil before putting decent stuff in.