With the help of TrailriderJoe, we tore down my 01WR426 today to troubleshoot a hard starting/non-starting issue. This bike has somewhere between 13,000 - 15,000 miles of singletrack since I bought the bike new in 2001. The valves had never been adjusted to this point. Unfortunately with my current feeler gauges, I cannot actually measure the middle intake valve because the feeler doesn't fit between the casting, so that particular valve clearance had not been measured recently. The other 4 valves clearances are still within specs, 0.10 mm for the intakes (0.10-0.15 mm spec), and 0.20 mm for the exhausts (0.20-0.25 mm spec). What we found to be the culprit of low/no compression was the center intake valve that had hammered the valve seat, leaking compression and now it definitely needs to be recut.
Is there a well respected shop that folks use to cut valve seats? I know Myler's is the one-and-only for repairing radiators, is there a similar shop for doing head work? I am in Michigan, so someone local would be a bonus, but I can ship out the head wherever needed. I definitely want to have someone who knows what they are doing, and will do a quality job versus a some hack who is just cheap.
I would assume at this point I should do all 5 valves and seats just for the sake of being thorough. I am not decided yet on SS versus the titanium valves, but I know cost is a big difference. I am inclined to go with OEM titanium just because that is what the bike was actually designed for, and they did last for 13.5 years at roughly 1,000+ miles of singletrack a year.
Any recommendations for shops?
I was reading old posts and it appears that the center intake is typically a culprit for valve failures, wearing first or whatever valve problem exists. Is there a specific reason the center intake valve is the first to go?