2003 225 4cycle yamaha fuel in oil

[Bruce Rae]

I have fuel in my oil. I have done a leak down test with normal results. anyone had this problem?

[boscoe99]

Quite a few.

But in the overall scheme of things it is not a particularly widespread problem.

Did you have the oil analyzed? If so, what was the percentage of gasoline? A small amount smells and seems worse than it might appear.

See the Gas in oil post which has recently been thrashed around.

A leak down may indicate that both the intake and exhaust valves and/or a head gasket are leaking like sieves. Not sure what bearing this will have on the making oil issue.

[Bruce Rae]

I think that there is only fuel or water that can get in the oil and it is so excessive that it runs out the dipstick and obvious that it is fuel not water. the leak down test was to determine if there was a broken or stuck ring causing raw fuel to enter crankcase. im thinking maybe a crankcase vent problem but not familiar these engines. does anyone know if they have something like a PCV valve.

[99yam40]

Running too cold( bad stat), running at low RPMs for long periods like *****ing,cylinder not firing and burning the fuel in there, and over propped are common causes

Injected motors have problems with leaking injectors maybe

[rodbolt17]

no PCV valves, not that a PCV valve could remotely cause a fuel in the oil on any fourstroke.

if the leakdown is all less than 10% then we can look at how can gasoline get from the VST to the engine oil.

past the rings due to a cyl misfire.
past the rings due to an injector leak.
past the rings due to over propping.
past the rings due to an over rich A/F mix due to undercooling/excessive idle speeds.
in the airbox,down the intake runner and past the rings due to a leaking VST needle.

starting to notice a pattern here??????