Evening Martyn,
A pattern gasket between the right hand crankcase and the outer clutch cover casing blew with me, oil all over the back tyre!
When you strip the motor you will see that the width of the mating surfaces at ~10:00 o'clock, behind the kickstart, when viewed from the off side of the bike is very narrow. The difference in the quality of the 'pattern' and 'genuine' gasket material was very marked. The 'pattern' being made from thinner material, prone to deformation.
I check all case mating faces against a sheet of plate glass and try sliding a 2 thou feeler gauge between the surfaces, others may use a different thickness of guage. Also lightly paint a gasket cement onto the case surfaces, I use Honda's cement, before assembly. Torque to factory pattern and values.
Once motor has been re-assembled, run up and warmed through and cooled, check the torques where possible.
Cheers, Bill
