Had a Ueda 45 in the good ole days.Engine had an exhaust restrictor and airbleed carb if I recall.The engine was eventually bored out to a Ueda 55 with a single plug which eventually led to a twin plug version..Calling it a powerhouse was really stretching it, even the bored out 55. It was what I would call an OS appreciation engine! Got an OS max50 and never looked back.