QUOTE=Scootmeister;327744]Hey 5-7, how well do your gears shift? My latest project has a 7-speed Shimano cassette with grip shift and I can't decide whether to keep it or yank it off. Also, you don't hear much about Tanaka engines. It sounds like you are satisfied with yours. My guess is they are Japanese and of good quality like Hondas (though the Honda 50 is now being made in China). I agree with all of the comments comparing the performance of go-karts to MBs. When I was a kid we used McCullogh and West Bend engines on our karts. These engines were high compression, often boosted with ether, and they had fantastic fully adjustable diaphram carbs. Those engines were so powerful they ate clutches and sprockets for breakfast!! I wonder what karters are running today.[/QUOTE]
Scootmeister, they shift as smooth as butter, after I learned to slack the throttle, pedal and shift gears, then get back on the throttle. No broken chains, cassettes or derailleurs after that. The SBP chainring bike sprocket and the 8mm engine chain and sprocket are indestructible. I was worried about the $20 pocketbike tranny's tiny gears and teeth. I've had a tranny seal, circlip and bearing wear out. However, they're so cheap and easy to replace, if and when the time comes. All pocketbike trannies whine in protest, but they hold together. I use automotive grease instead of oil, in the tranny.
Four mounting bolts hold the engine onto the bike. Disconnect the throttle and killswitch, and the engine falls away from the bike. Remove the transmission shaft sprocket and two more bolts, and the tranny slips off.
The Tanaka engine is so reliable that you just need to wipe down the oil spray and concentrate on the rest of the bike's maintenance needs.