There was a simular clicking porblem on an ASP .61, the clicking noise was caused by a faulty bearing where the crankshaft exits the case.

Best thing though is to send it back to where ever you got it from to get a serice or replacement, if you got it from Just Engines they are good for service.

I don't recommend opening it yourself unless you are a mechanic.

Hope it turns out ok!

Shahid