I have removed the head a cylinder to get bored. I removed the clutch cover to get the clutch off so I can change the cam chain. I found what was left of a spring, I think, in a cavity towards the front part of the engine that must of got chewed up and spit there. Nothing I can see is missing where I am at, the book does not match the model I have and the up load here will take 2 plus hours on my dial up. I just brought the bike home a week ago so I do not know how it really ran but it did. The shifter feels good, I can see inside and all the springs are in the counter balance gear. Only a guess but it looks about 7-8 mmx with about 9-10 wraps. Any body here ever tore into one of these older type DRs.