[Jack21]

Thanks everyone. Engine had a standard warm street motor rebuild balance. It was not internally balanced. The balancer left the builder the option of leaving the counterweight off if the engine was internally balanced. Of course, if that were the case, the flywheel also would need rebalancing.

Anyway, I'll check the part number which should be stamped on the unit. Think I'll pay a visit to the shop that did the engine and get their opinion. (Which is why I like locally built engines) It's just enough to be annoying.

There is no way for the counterweight to come out. If it came loose, it would make a hell of a racket.