Mend > Motorcycles

how can i stop the oil pumpimg out of the crankcase breather pipe?

Hi Adam, thanks for the advice on the oil type, i have checked the oil level it is o.k. i have used semi synthetic 10 /40 oil, the oil is still pumping out the breather pipe when i rev the bike, i am now thinking a seal has gone possably behind the clutch basket as the breather pipe is on the clutch side? the guy who owened the bike before me fitted a gear box shaft are there seals he should have replaced here? any ideas.
Thanks, Fred.

fred donaghy
April 2006

Vehicles, Motorcycles Oil Pipe Level

sorry the right hand seal that may be gone is called a crank seal they are only about £5.00 each but you need to take the clutch and the gear ont the end of the crank off too to get to it ,you can simply lever the seal out and tap the new one in with a large socket making sure it the right way round and making sure the lip on the seal doesnt get curled over when you are fitting it ok fred.

adam bike doctor
April 2006

Thanks for the thanks fred ,the only seal that will cause the crankcase to pressurise is the one on the right hand side as the pre compressed fuel air mixture will be able to get into the gearbox area and cause the oil to froth and basically stir it up alot.any other seal is irrelevent to the problem you have they will only cause an oil leak or if the left hand crankseal goes it will make the bike run badly.incidentally the right hand crank seal will usually allow extra oil to get into the crancase where the crank is and make it alot smokier and the smoke smells unusual unlike the burning 2 stroke oil.ok hope that helps you mate,adam

adam
April 2006