Ok, so I've bought a 81 GS850G and I'm fixing it up. When I bought it it squeaked especially at very low RPMs, even more so when the bike was only turning over. It had a knock so I took off the cover and checked the valves. Every single valve was out. maximum clearance for this bike on both exhaust and intake is .003, and I had one at .011 :eek1 Tomorrow I'll go and pick up new shims. Point #1 The person I bought it from said that he'd ride it for a while and then it'd bog down and die and then he'd let it cool off and it'd ride great again. Point #2 When I took off the valve cover most of the camshaft was bone dry. I coated the cams with oil manually, then the bike turned over much faster than before, and that squeak was much quieter. You can see from the picture of the cover that there was just debris that looked like worn shim and cam shavings, and you can see how dry it was. This is the top of the engine after my manual oiling job. Last fotos: cam shafts So should I just assume that it's an oil pump problem, or clogged lines, or something else?