Motorcycle Repair: shifting problems, retainer plate, clutch lever

Question
i can shift from 1 to 2 gear but on 3 and 4th i have to double shift it does it 80% of the time i owen a cm200t honda 1981 i used 10/30 motor oil can it be my clutch and i have taken it apart and have viewed the clutch ? and the gear shift retainer plate i can manully shift it into all gears what can it be please help and do you know any books which can tell me how everything works or corresponds to each other  

Answer
Guillermo, the clutch must release cleanly for the transmission to shift properly. That means that you should have just a little free play at the clutch lever, so the cable and release mechanism can fully disengage the clutch from the transmission. If the clutch plates are all flat and nice and the release mechanism is doing its job, then the problem is probably internal.

http://www.dansmc.com/gearbox.htm
http://www.dansmc.com/gearshifters.htm

You don't mention the miles or history of the bike, but if it has a lot of miles and has been abused in the past, then the shift dogs are probably rounded off and trying not to engage, unless you take all the torque off the sliding gears. The shift forks may be excessively worn, as well. Gotta tear the whole motor down for repairs on this engine, as the crankcases are vertically split.

Bill Silver