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Yamaha 115 4 stroke gas getting in oil

t_wysong

New member
When I recently checked the oi

When I recently checked the oil level gas had accumulated in the crankcase and mixed with the oil. I replaced the fuel pump thinking that the diaphram was leaking fuel into the crankcase. After running the engine on the lake for approx 5 hours (two trips on the lake) fuel is still getting into the crankcase. How can fuel enter the crankcase other than through the fuel pump? What can I check before taking it to the dealer?
 
More information: The motor i

More information: The motor is a 2003 fuel injected 4 stroke Yamaha. When operating it runs normally with full power and acceleration. I'm stumped.
 
check t-stats and that engine

check t-stats and that engine is coming up to temp. If its running cold it will pass gas( bad phrase) past the rings and into the crankcase.
 
"Having the same trouble with

"Having the same trouble with my Yamaha 115hp 2004. Took it to the shop last fall and they said to run "ring free" through it. I added the ring free this Spring, took it out once, and came back with gas in the oil. It idle rough, stalls occasionally, but seems to run good at cruising speed."
 
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