Triumph Repair: tr250 head gasket leak, head gasket leak, chalk mark

Question
I installed an aluminum[TRF] valve cover[with vent tube] and now oil is heavily seeping from the head gasket down the left side of the engine.  I also plugged the tiny hole in the valve cover cap as it was weeping oil.  Is the valve cover vent to the carbs not sufficient or do I just have a bad head gasket.  I already re-torqued but the nuts didn't tighten.

Answer
Tom,

Carefully de-oil the engine.  Once it's dry either put a chalk mark all the way around the head just under the valve cover or put something on the head that will show if oil is leaking down from the valve cover.  Go for a good test drive and look for oil marks in the chalk.  

That's the more likely source as the aluminum valve covers typically allow leaks along the mating flange.  

If it's definitely coming from the head gasket then you have no choice but to replace the head gasket.


Cheers,

Jim