My 1954 88 has a fairly bad oil leak from the dynamo clamp stud area. I have replaced the base gasket and cannot see any obvious cause of the leak which is still present. Has anyone had any experience of a leak due to a defect/crack around the barrel stud stub? My barrel has a hex head set screw welded to the barrel - is this the standard or should the cast iron be tapped for a stud?
Regards
David Lloyd
Barrels & Breathing
Both the barrel flange and crankcase mouth can twist with aging. This being due to stresses induced into the castings during manufacture. The crankcase top is an easy fix by using some wet & dry on a flat surface after removing the barrel studs. The barrel is not so straightforward due to the cylinder liners but a straight edge might highlight some of the raised spots.
When my 650 barrel began weeping at the base joint I just replaced the 12 thou thin gasket with a later 25 thou thicker item.
As Lance mentions above getting decent crankcase breathing is generally 50% of solving this kind of problem.
- Log in to post comments
Hi, David.
I recently had a similar leak on my 66 650SS which appeared to be coming from where the base gasket had split on the outside of one of the stud holes. However, I eventually discovered that the breather pipe to the top of the oil tank had a kink in it where I had it routed under the magneto and it was this which was over-pressurizing the engine and causing the leak. Once I'd addressed the kinked pipe it's been oil tight since.
Just a possibility to check.
Good luck.