Yamaha 4 stroke fuel in oil

[Olddogrj]

2000 F115 Check oil, ok, go fishing, come home and check oil couple days later 1/4 inch higher on stick than last time checked. Wait couple more days and check it, now 1/2 inch higher on stick. Service people claim they smell fuel in oil and checked fuel pump, it checked out ok. It's not water, cause oil when drained is not cloudy as it would be if water were getting in. Been doing this since new. Ymaha says run it harder. Got 70 some hours on it and am about ready to go back to a 2 cycle. Any suggestions or solutions out there?

 

[JB]

Re: Yamaha 4 stroke fuel in oil

Howdy, Olddog.<br /><br />I have heard of this problem with the Yammy EFI 4 strokes but I haven't heard a diagnosis.<br /><br />I believe it is fixable, but I also believe that it is up to Yamaha to fix it. They need to put a pressure relief system on the primary pump, which still hold pressure when the engine is shut down. The question is where the heck to bleed the pressure to?<br /><br />I would definitely disconnect the fuel line when putting her up for more than a few hours and see if that makes a difference.<br /><br />Good luck.

 

[Oil Man]

Re: Yamaha 4 stroke fuel in oil

The general consensus on at least one other board (with good results) is to run it hard.<br />Apparently, the rings on the Yammys take a while to seat and the hard runs help that out.<br /><br />Dave

 

[boatneck]

Re: Yamaha 4 stroke fuel in oil

I have a 2001 Yamaha F115 4-stroke which had the same problem during the breakin period. My dealer told me to ignore the constraint on rpms and let it rip in order to seat the rings. He tells me that this is what Yamaha recommends and would not affect the warranty. So far, so good.