Originally Posted by
Mike Sal
I examined the pistons very carefully, before & after cleaning them, & could find no evidence of contact with the exhaust valves. Root cause of the failure was the tensioner (above the waterpump). The tab that bears against the spring broke, allowing the tensioner to unwind. The intake cam jumped time & crashed. The exhaust cam stayed in time & survived.
I plan to install the head tomorrow. I may pull one exhaust valve from each cylinder just to double check.
I put the cut off old stem into the mandrel so that the set screw goes into the groove for the keepers to ensure it stayed in place.
Mike Sal