AMA Supersport Racer
Join Date: Apr 2011
Thanked 199 Times in 174 Posts
Feedback Score: 0 reviews
Valves beyond adjustment, heads coming off.
I haven't seen this before, but I guess not many go enough miles. Last time I checked valves [63,000 miles], cylinders #2 and #3 intake valves were very tight. Being my first time adjusting, I thought it was my technique. I could get the feeler inserted but it took some effort. I put some smaller shims in but not small enough. Fast foward to now, just over 82,000 miles and I'm doing them again. Again, I find just those valves tight, can't get any feeler gauge in with any effort. So I check and calculate the other valves, then install everything except I put no shims on the #2+3 intakes so I can figure out what I am working with. Turns out, those 4 valves are way off, no shim goes small enough to compensate. That should mean my valve seats for those intakes are gone, and need new seats machined in. So the head has to come off.
The crazy part is the other 12 valves are all wearing pretty evenly and slowly, with the exhaust valves all wearing exactly the same each time they are checked. So yes, keep up on your valve checks. If you aren't sure, get another opinion. Might have saved me some hassle if I had.
'06 F4i- Yoshimura RS-3C, Racetech springs and valves, Ohlin's rear shock, steel brake lines, 520 conversion. 87k miles and counting.....
'08 600RR- Stripped trackbike. CRG shorty brake lever, goodridge front brake lines
'15 1000RR- weekend toy
------Disclaimer: I can't spell------