Mower starts but wont stay on. ran fine for 30 min but then started burning oil (blue smoke) and lost power.

mine recommends using only detergent oil rated API service classification SG-SL. Sounds like an older model and the synthetic may be to thin. Try changing the oil to a SAE 30 to see.

Black smoke is generally indicative of a rich fuel system. whitish blue smoke is generally burning oil.
It sounds like there is something wrong with the fuel metering at full throttle. You might check that the mechanical compression release isn't coming on when you go to full throttle.

Sounds like the engine is tired. Blue smoke is oil burning. Hard starting is oil on the spark plugs and/or low compression. This also can be due to someone adding too much oil.
Sometimes, the carburetor Needle valve hangs u pa bit and the Crank case oil gets mixed with gas so now the oil level is high. Too much oil in a motor is bad too, that would cause theblue smoke too.

smoke smell like burning oil or hot antifreeze..

Hi, change the oil and your problem will be solved. Basically it was over full because fuel has by-passed the carby needle and leaked into the sump while its been sitting idle. Regards Phil.

check your oil level in mower. probably too much.

valve seals are going. when car sits excess oil gets past the valve seals then when you staRT up it burns the oil off then runs fine and no more blue smoke. It is fine to run like that had the same in a dodge caravan 1996 6cyl. ran another 100 000 km. and still ran fine got rid of it for other reasons.

I would need the engine numbers to tell ya what to do for sure. It sounds like the engine is too full on oil. Check oil levels carefully.That engine capacity is only 1 pint/16 to 20 oz's ALSO you friend may have cleaned under your deck and turned the mower with the aircleaner DOWN. That causes oil to flow from the crankcase into the air cleaner and muffler.That aircleaner is a dry paper and should not have any oil on it, If this is the case then the oil accumulated in the muffler will burn off in time. Oil soaked paper aircleaners will cause this engine not to start.IT CANT BREATH

does it turn over slow or fast if it turns slowly thats the problem so it could be battery or starter they have to have a good amount of rpms to burn fuel right when starting if not it floods out the engine with gas hope this helps thanks wade