if its a 3 speed you want, get a honda 50 bottom end, rip the top end off pull out the push rod put a blocker plate on where the top end bolts up, pull the flywheel drill out 6 rivets and mount a sprocket on it, and a chain to you engine, you dont need a clutch since the 50 has one built in, and you will have a 3 speed tranny thats closer to 15 pounds then 90, not to mention setting up a kind of shift linkage for it would be a *****, i have pictures of the 50 tranny set up on my camera i can post tomorrow or something, its not 100% finished yet, and the tranny will hold up, i built a 140 stroked pitbike engine with one of these 3 speeds, and it works good clutch slipped a little though,