here is what the specs are and where mine are at.
Exhaust valves should be between .20 to .25 mm
mine: exhaust valve - left at .229 mm right valve at .203 mm
intake valves should be between .10 to .15 mm
mine: intake valves - left at .102 mm middle valve at .10 mm right valve at .102 mm
I looked at all the camshaft lobs and they have no marks on them and no signs of wear at all. the camshafts gears look like new. so does the chain and chain tensioner. Inside the valve cover area, it is very clean with just oil coating everything. NO signs of dirt, carbon, gunk, loose metal pieces (of any kind), at all. Did not even have to wipe anything off. That is amazing for a bike that is almost 10 years old.
The spark plug looked great but I did have to adjust the gap a little. Over 5,500 miles on the plug I put in when I bought the bike two years ago and in comparing it to my brand new spare, you can hardly see a difference in wear on the electrode.
The bike starts usually 1st kick cold or hot and runs perfectly. If it starts getting hard to start, I will then adjust the valves to be more in the middle of the range but for now I will not mess with it. (will keep an eye on it since close to the tight end of the spec).
I change the oil with Rotella T 15-40w always between 500 to 600 miles with filter. Also clean the air filter at the same time.
All I can say is I got very lucky when I bought this bike used and their is no doubt in my mind that Yamaha builds one hellava long lasting motor.
I posted this just for information on the longevity and wear of the valve train on my bike.
Edited by jcbikes, August 18, 2011 - 09:57 AM.