thank you for the replies. i did what you suggested to burn off the oil out of the exhaust.
i could be wrong but to me it seems like after running for a while enough oil is being pushed into the manifold that it is going through the carby,mixing with the petrol & burning off in the cylinder which is causing the huge amount of smoke
i did 1/2 an hours mowing without the breather hose connected to the carby & it ran fine,just had the constant spitting of oil out the hose.i was wondering if there could be any harm in using a catch can for this ?
re the mower blowing smoke before hand,it`s only ever been a tiny amount but i had always thought is was probably worn rings
cheers
jason