I have a 2002 warrior 350. I was riding at the track when I lost power and got a bad engine rattle. I took off the valve covers and found the lock nut on my exhaust valve had come off. I believe the nut was the rattle, and the screw backing out was the loss of power. I bought a new screw and nut and placed them in. My understanding was the exhaust asjustment for the warrior was 0.006-?
so I adjusted it to 0.007 TDC cold. I checked the compression and got 155psi on my old guage. The quad seemed to idle well. It sounded to me like it had a bit of a puffing sound that didn't seem normal (don't know how else to describe it). It seemed to respec correct, so I took it on the street. It had very good power in 1st, 2nd and 3rd gears. It didn't sound completely healthy in the high RPM in 4th and 5th gear. I let off the gas for a second, and when I hit the gas again it completely shut off. After I pushed it home, I took off the cam sprocket cover (which previously everything looked healthy). The cam sprocket turns when I hit start but the cam does not. One of the holes in the sprocket appears to have flexed and I believe the lock bent out and the sprocket is spinning freely on the cam. I haven't done anything else with the quad since I have seen this. The shop guys told me the sprocket would have broke if the valve was adjusted too tight. They told me to put a new sprocket in it and readjust it again.
Any insight on this? I don't want to throw parts at a quad with a problem, but I also don't want to tear apart a top end with 155PSI for no reason. I was going to take the advice and simply order the sprocket and try again, but I just don't see why the sprocket would have broke, and am afraid something greater is the problem. I can't recheck the compression to see if the valves are burnt up w/o it... Advice? Help...
I'm going to be buying a YFZ 450 very soon or I'd just tear it apart and put a hotcam in it. I'm going to keep the bike as a spare/friend bike and want to keep it simple and cheap. It's important to me to make it as reliable as it once was.
Thanks