Shaun is one of if not THE most knowledgable moped mechanics I have ever run across. He is a super nice guy to boot. Shaun built a 50 cc engine that could hit 83 mph and later another that did 93 mph. He has been in the biz about 20 years from the good ole days of the 70s and 80s when mopeds ruled the land.
He was in with and still is with Myrons mopeds which became primarily a goped shop. Last I talked to hime he had plans to establish his own web site.
Great guy, honest and helpful, give hime some business if you can.