"'Mike'" wrote in message
...
Air filter VERY important. Clean that before you do anything else. The
machine demands air to run, blocked filter starves it of air. FULL STOP
ENGINE.

That one caught me out. I had tipped the mower over to sharpen the blade.
When I tried to start it again it wouldn't run and was very smokey. Turned
out the air filter paper was flooded with petrol and dust.