NON ST, I'm doing a valve clearance check on a friends bike (04 Yam R1). This bike has about 24K miles. He told me he had a shop do the last check. Looking at his air filter, I doubt they even pulled the air box. Anyway, reason for the post is one of his valve clearance gap is huge.
All exhaust are in the middle of the range (.21-.25mm). Majority of the intake are dead center as well with one a tad tight but tolerable (.11-.20mm)
The intake valve in question is #3 cyl, facing engine left to right (closest to cam chain), valve #1 has a gap of .490 mm. I re-did the check about 6 times, same thing.
I'm not amechanic so I don't want to pull the cams and shim it down until I know if this is an indication of something major. I've personally never seen one this far out of spec.
Anyone seen this, is it serious? Any suggestions? I'm tempted to button it back up and tell him to take it into the dealership, or at least avoid the previous shop he used. Anyway, I wanted to check with someone who may know if this is a real problem.
Thanks and appreciate the time.
Denny
All exhaust are in the middle of the range (.21-.25mm). Majority of the intake are dead center as well with one a tad tight but tolerable (.11-.20mm)
The intake valve in question is #3 cyl, facing engine left to right (closest to cam chain), valve #1 has a gap of .490 mm. I re-did the check about 6 times, same thing.
I'm not amechanic so I don't want to pull the cams and shim it down until I know if this is an indication of something major. I've personally never seen one this far out of spec.
Anyone seen this, is it serious? Any suggestions? I'm tempted to button it back up and tell him to take it into the dealership, or at least avoid the previous shop he used. Anyway, I wanted to check with someone who may know if this is a real problem.
Thanks and appreciate the time.
Denny