During the last couple decades I have rebuilt dozens of Honda 4 strokes and most of the time this included installing a new cam chain. The way that I check a chain IN BIKE is clean a section of it it real well to remove the oil, hold the chain firmly between my fingers (capturing a few lengths between the index/thumb on left and right hand) and push/pull while watching for play between the pins. Most of the bigger XR's use a hypo chain (multiple plates forming a gear type of area for the cam sprocket to land in) and this method of checking has ALWAYS proved true for me.. This style of chain is very expensive/heavy duty but still suseptable to wear problems resulting in some MAJOR concerns if not properly maintained (replaced at stated intervals)..
Now for the Yamaha question.. I was at a friends house helping him rebuild his 2000 YZF. He had a top end noise that majorly increased with no strain on the motor. He swore that it was rod related - I said it sounded to light for a wristpin/not low enough for a rod bearing. I suspected cam problems.. Once down I was VERY impressed with the internals of the Yam - except for the cam chain!! It was tiny!! Looked like something out of a Honda 70 motor.. I did the exam and found plenty of movement between the pins. Got it out and it definitly showed major ARC on the bench!! My buddy is still going for the rod replacement but I told him he should hang on until I have a chance to run this little survey!! So How bout it ch'all? Anyone else had simular problems with the cam chain stretching? Could this be a "weak link" (place my smily here)..
Woodsy
Now for the Yamaha question.. I was at a friends house helping him rebuild his 2000 YZF. He had a top end noise that majorly increased with no strain on the motor. He swore that it was rod related - I said it sounded to light for a wristpin/not low enough for a rod bearing. I suspected cam problems.. Once down I was VERY impressed with the internals of the Yam - except for the cam chain!! It was tiny!! Looked like something out of a Honda 70 motor.. I did the exam and found plenty of movement between the pins. Got it out and it definitly showed major ARC on the bench!! My buddy is still going for the rod replacement but I told him he should hang on until I have a chance to run this little survey!! So How bout it ch'all? Anyone else had simular problems with the cam chain stretching? Could this be a "weak link" (place my smily here)..
Woodsy