YZFR6... ooodles of HP
Valves are seating based on those numbers. De carbon and call it a day. Remember to keep the valves accurately marked to what guide they belong to.
I hope that is the case that he just didn't do it right. But for awhile afterwards the bike was running far better so I'd like to think he was somewhat competent. It wasn't a dealership shop either. I tried going there the first time and there is no way they adjusted my valves.If you "had them adjusted" only 10k ago, I'd wonder whether whoever did it, actually adjusted them... or maybe adjusted them correctly?
Only possible factors that that would cause such rapid wear are constant high-RPM, poor lubrication and/or junk parts.
Checked mine at 50k (engine never having been opened) and didn't really have anything that needed to be done; particularly since you can't get 0.01 increment shims.
Thanks 8ball. Ill try and find a worthy machine shop near me and see what they say, but i cant imagine it will be cheap either way. Yea i thought about a used head, hard to trust any ebay sales though. Im in a pickle. I cant imagine a summer without riding but dropping big bucks on a bike i planned on selling in the near future doesn't make much sense. Uggh.Sounds to me you are correct. It is probably worth taking it to an auto machine shop and seeing what they suggest. (Take the cams with the head). They may be able to resurface the seats, and mill the stems down to get it back to the correct valve height. That’s what was done in the old days. In this day and age, IDK if anyone does that, and what they would charge. It might be cheaper to get a good used head..... but then, I guess you’re rolling the dice on a used head.
The seats are actually hardened inserts pressed into the head, not the actual aluminum. They are replaceable at around $5 a piece (then you need someone that can press them in safely.Since it is the physical aluminum of the head, It can mushroom beyond sealing and or ideal flow. But you get low compression when the thing is deformed too much. It's 3 or 5 angles to limit seat contact and maximize flow at various openings.