1979 850G just spit out a shim

[prosolar]

Ah it was definitely not the .5mm too small shim. I'm also sure the adjustment was correct. Ya i for sure wanna find the rest of the shim... I've been maintaining and riding gs bikes for years never had this happen but I've heard of it happening!

[tkent02]

I have heard that sometimes carbon can build up in such a way that the valve is held open slightly when you rotate the engine by hand. When you adjust the clearance it is a false clearance, it is ony accurate until the chunk of carbon falls out. You get it hot and wind it out, the carbon falls or burns out, now the clearance is much too big. I bet if you put the same size shim back in it's way too loose now.

[prosolar]

Well I guess we'll never know now if the clearance was off because the cam and bucket will have to be changed. It was a non runner when I got it, and although I got it to run briefly before I tore into it, I found all four intake valves less than zero clearance... But it does look like clearance opened up, one of the other intake valves was .09mm. I think I have all the parts I need, cam from an 1100G, buckets etc. now if I can just find the rest of the shim...