iv just changed the r/h crank case on my trekker now it wont start i have spark and compresion but it wont start iv tryed covering the air filter end of the carb to get fuel threw and nothing also tryed some fuel down the plug and nothing it was running fine before i changed the casing eant advice would be helpfull

john, March 2011

Hey my bike will not start but when it does flames came out of the Exhaust And when it's does start its sound funny and keep cutting out but the lights work pls text back need help xx

Kirsty Retallick, December 2015

I'm looking at one on sunday and by the sounds of it its got the same problem,i'm going to check the brushes on the magnito

gary, June 2011

This goes back to me motorcyling days ... um er brum brum ... is your machine a 2 stroke ... well the crank case needs to be airtight because I remember that it is used in part of the 2 stroke cycle. It could be you are loosing pressure and that the mixture is not attaining sufficient pressure as it is transferred from crank case via a transfer port hole into the upper cylinder. It looks as if there is a faulty crank case gasket ... they are usually made of paper ... you could try squeezing some gasket paste between the two case halves but I don't think that will work as it won't cure as there is insufficient heat. Refitting crankcase gasket seems the answer.

Nyge, March 2011

did you use a new gasket between the crancase halves when you did it or use same sealant on it ?as this will also stop any transferral of new gases into the compression chamber

adam bike doctor(of milton keynes motorcycle centre), March 2011

iv replaced the seals,bairings oil pump seals ect got plenty off compression, spark ,and fuel its doing my head in iv spent 3 days on a coupple off hours job was running good untill i changed the r/h crank case due to the exhaust mount braking

john, March 2011

could be worn crank case oilseals. it;s best to renew them when re building 2 stroke engines.

rayb, March 2011