they are solid little engines. the casting is really nice. they start easy...everytime.
I'm squeezing about 25 mph out of my trike. We have members from eastern europe who really beef them up to race. http://www.motoredbikes.com/showpost.php?p=56990&postcount=1
There was a Russian guy who joined this forum(sorry,can't remember his name) and he said his engines were terrible.
Seems strange cos that's where these Happy Time engines are supposed to originate from arn't they....clones of 1950's Russian engines? http://www.motoredbikes.com/showthread.php?t=8125