Cam Timing Question

Well obviously, it will depend on how much wear or chain stretch has occurred, but it can get pretty high, like upwards of 10° to 15°. I think member 2Many has noted about 10° on his XS1B with a badly stretched chain. The points models warn you of a badly stretched chain - you run out of adjustment on the points plate. If I take one apart with anywhere near 20K miles on it, I replace the chain. I'm not saying the chains are junk and can't last longer than that, it's just that most weren't maintained properly. They weren't checked, adjusted, and kept properly tensioned. Someone posted on here a few years back that a long time dealer told him you should check the chain about every 1000 miles. I think the manual tells you every 4K miles. So, even if you followed the manual, it seems that still wasn't often enough. I've gotten into the habit of checking mine every time I change the oil, about every 1000 to 1200 miles.
 
Thanks for that, about the range I was expecting. I was trying to determine the significance of a 3 degree advanced cam timing error with my original rephased crank. This one was done cutting a new notch in the drive sprocket instead of removing it and rotating it to the new position. The crank in the bike now was done by Hugh and he does it the more correct way by removing and rotating the sprocket on the crank.

I wonder how much chain wear resulted in "nominal" cam timing in the eyes of the engineers at Yamaha.
 
Back
Top