hey, i recently got a 85 tomos a3sp running, and everthing was going good until i tried to ride it. It works fine in its low gear, but then starts jerking randomly when i get to the speed where it would shift up. I put fresh ATF oil in, and used the (side drain??) to get it at the proper level. Is there anything I can do easily, or will i have to take it all apart.
p.s. thick white smoke from the exhaust = carbon buildup??