Mercury 50 3 cylinder with fixed head, oil tank filled with fuel

[Stubber]

Hi, just took the cowling off to find the 2 stroke oil tank filled to the brim and it was half full last time I looked, took the cap off to find fuel and oil in tank.
Obviously the one way valve on the fuel line next to the oil pump has not worked correctly, is this due to me leaving the fuel line connected and pressure building up in tank or just the valve being no good, has anybody else had this issue?

[jeffstevens763@g]

As a guess fuel tank breather shut tight pressure built up in warm weather which can be quite significant and pushed pass the valve taking the easy way to release pressure through the oil tank?

Cheers

[Stubber]

That was my guess Geff, just hope its ok, will drain oil tank tomorrow and see what its doing when running

[jeffstevens763@g]

Hopefully when running even if the non return is a bit weak the fuel will be pulled to the carbs creating a negative for the oil to flow. Under normal conditions I don't suppose the non return needs to withstand high pressure but when the fuel line was on it was a different ball game. I would swap out the non return in any case to be sure and leave the breather just cracked to prevent pressure build up.
Hope it's ok cheers

[Stubber]

Yes will do, just ordered some parts today for another engine, typical

[Stubber]

Took valve out today to find it passing both ways so presume its knackered, new one ordered. So this is a problem leaving tank connected so will have to remember to disconnect in future, learn by my mistakes

[jeffstevens763@g]

Originally Posted by Stubber

Took valve out today to find it passing both ways so presume its knackered, new one ordered. So this is a problem leaving tank connected so will have to remember to disconnect in future, learn by my mistakes

yep we all do it stubber still sorted now cheers