I see. The manual makes a great deal out of cleaning carbon from the combustion chamber and exhaust port as part of the maintenance procedure, and I've already put my stock carburetor and air filter on, as well as fixed any air leaks. It runs consistently at full throttle, but just barely breaks 25 mph. Judging by the amount of carbon I found in the exhaust port while cleaning the pipe, there's probably still a fair amount in the combustion chamber.
So I suppose my next step will be a thorough inspection of the engine and transmission. Maybe a compression test as well? How many kicks will give an accurate reading? Just once? And lastly, the manual only gives a compression ratio of 6.5:1. How does this translate to PSI?(edited)