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Valve Adjustment Experience

4K views 12 replies 6 participants last post by  MELK-MAN 
#1 · (Edited)
who has done or checked valves on R6's? what mileage did you check and what did you find on the first check?

Reason i am asking, i have an 05 R6 with 10k miles, motor is out of the bike so i thought id check the valves, did it by the book with each piston at TDC verified and with cam lobes facing out away from one another like book said. Buttt with only 10k miles on my bike all of my exhaust valves are to tight and 4 out of the 8 intakes are tight also, the other 4 intakes are in the preferred location of .15

that leads me to believe i did it 100% correct but only having 10k miles im not sure why i would have so many valves tight. bike has had a stock pipe on it its whole life till i got it 2k miles ago and seemed to be babied as its literally showroom clean.

Cyl #1 Ex .203 .203 IN .152 .152
Cyl #2 EX .203 .203 IN .127 .127
Cyl #4 EX .203 .203 IN .152 .127
Cyl #3 EX .229 .203 IN .152 .127

Any thoughts would be appreciated.
 
#2 ·
Manuals says around 26k miles for a valve check. Many claims that the motor can run 50k+ without a single valve being off specs.

Strange thins is, they don't loosen with wear, they tighten... So it's pretty weird to have these numbers at only 10k... Are you the first owner?
 
#3 ·
you say the bike is 'showroom clean'.. imho that just means someone took the time to make it look good.

do you know for sure the bike was not raced/tracked from its first mili on the odo?

It is odd that you would have so many tight valves, and quite a bit out.
When i checked it on my old 03 it had almost 30k on it, with a few trackdays, and not 1 was OT.

It sounds like you did check them correctly, but if you still have it apart, have another go at it to be sure, then just replace what needs replacing and pat yourself on the back from preventing some damage.
 
#4 · (Edited)
thanks guys, i am going to double check it this afternoon again to be sure but nearly 100% i did it all right, thats what struck me as odd is everyone says the valves are usually good at those 25-30k intervals and at 10 mines not.

this is like my 15th bike so i know what im lookin for when buying bikes and theres noway this has 2 or 3 times the mileage on it im very sure of that. i worked for a yamaha dealer for some time and have seen bikes in the showroom not as clean as this one is, not to say it couldnt have been riden very hard or high rpms without up shifting so idk what could have caused it but im gonna go ahead and double check then get them adjusted to fall in the middle of that spec range. this is my second 05 R6 first one had 1800 miles on it when i bought it in 06 and this bike rides tighter all around with 8800 miles on it then when i got it. i've owned this one from 8800-10400
 
#5 ·
Odd Ryan just changed his around 10k BC they were out of spec. I did mine at 25k miles and they were quit a bit to tight.


why do they get tighter? Spring loosening up?
 
#7 · (Edited)
valve clearance gets smaller between the bucket and camshaft, because the valve stem comes UP as a valve wears.. have to picture in your mind the head with the valve train. A valve face wears, it flattens and mushrooms a bit, so the valve moves UP into the valve seat of the cylinder head. As a result, the distance between the bucket on top of the spring/retainers/keepers, move up toward the camshaft lobe.
Run em long enough, and there will be ZERO clearance, and you don't get the valve even sealing against the cylinder head valve seat.. loss of compression, hard starting, etc. because the valve is held OPEN a tiny amount.

no way should a 10k bike have tight valves.. but then how does a bike that is 7 years old (nearly 8) only have 10k on it?
and MY question is why is the motor out??
 
#9 ·
.. and the problem with lots of hours on valve springs, and the reason you replace valve springs (especially in race motors) is the risk of valve float at high rpm. There is a minimum spec length for springs indicated in the manaual, but if you are spending $60+ per valve to rebuild an engine, it's silly to not spend $9 or so per spring as well. If a spring wears, at high rpm, it may not pull the valve up as fast as it should. The piston is on it's way up and if the valve is a tad late in getting back to the head seat they make contact.. bad. not good. :) One time when you really need good springs is if you mistakenly downshift when you should go up, or down shift too many gears too fast and dump the clutch. There is NO rev limiter for overrev by way of downshifts.. if the slipper clutch doesn't slip enough, you could theoretically have an engine go beyond 16,000rpm. that is one surefire way to end up with broken valves and and expensive rebuild on a "to do" list.
 
#13 ·
this was not causing any problem.. in fact some builders will intentionally shim on the tight side of the range for better performance (but we are talking motors that are rebuilt each year).
since you have everything apart ya might as well re-shim. The steel valves on your 05 are much more durable than the TI valves of the 3rd gen motors.
 
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