[networktech]

I've been looking and asking all over. Get different advice. My mower will start fine and run good for a few minutes then all of a sudden it starts sputtering, smoking (greyish) and then die. If I let it sit for a while then it will usually start the same way and after a minute or so do the same thing. If I try to start again immediately problem still there and to get it started I either have to choke or set throttle all the way down to idle - just depends.

I was told it could be a crankcase check valve gone bad and allowing oil back into carb. I don't see a tube or a check valve - maybe it's behind the carb where carb mounts to engine? I took apart bottom of carb and both needle/seat seem OK (replaced last year) and float is still good. Any suggestions?

[ballengerb1]

Try running with the air filter and gas cap removed, just for testing purposes. Let us know if the engine runs better with this stuff off.

[networktech]

Actually, that's how I've been working on it. It makes no difference if I take off the gas cap or air filter.

[ballengerb1]

Grey sounds like fuel, white is oil. Remove the bowl again, after a moment does any fuel continue to drip from the needle?

[networktech]

No. It seals 100% if I remember. I will go out in a little while and check again to make sure but I think it seats well. Also, it's hard to describe the exact color but I think the smoke may be on the grey-white side.