I have a 1978 Km100, my friend gave it to me and the only problem was the flywheel key was broke and the rotary valve was stripped. I got it running perfect but it doesnt shift. i looked at the shifting mechanism and found nothing bent or stripped. when i push or pull on the shifter the shifting drum doesnt click into place all the way like if it were snagging on something. i split the cases and found nothing wrong with anything. if anyone has any suggestions i would greatly appreciate it.