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mschemmy24

2007 yz250f valve clearance

15 posts in this topic

I checked my valve clearance for the first time and need some help with my results. The manual said the range for intake is 0.10 - 0.15. My intake valves are 0.10. The range for exhaust is 0.17 - 0.22. My valves were 0.18. I am assuming that this means my valves are tight?? Since they are still in range am I okay to ride before shimmimg and just keep checking them until they are no longer in range? My bike starts with just a few kicks and runs strong so I haven't noticed any decline in starting or performance. Thanks for any advice!

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You're ok now but you're are at the edge of the range so you'll have to do it very soon. While you've got it apart, you may as well shim it. You'll need to measure the existing shims when you take them out before you can go back to the manual to figure out what shims you need.

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Thanks for the reply. I figured I was going to need to shim it soon. Does anyone know of a previously posted thread that could walk we through this process? I know in the part people have put video and narrative information about important steps and procedures needed to do this job successfully. Any help would be greatly appreciated!

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its easy, pull the cams, get a magnet to pull the buckets up, use the magnet to pull the shim out

the shim has its size written on it, ie 185=1.85mm

if your 185 is tight by .05(.10would =.15) then you go with a 180(1.80mm)

GL and happy hunting

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you're in spec so I'd let it go and check again in 15-20 hrs and see if they are moving.

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why chance it?

what's he chancing? tight valves don't lead to catostrophic engine failure, just sometimes harder starting and if they go to zero a burned valve....maybe.

I was at .002 when I shimmed recently. I checked them 20 hrs previously and you could barely get an .004 in...meaning just under tolerance. I shimmed them when I noticed my WFO, hi rpm, jetting was getting a little strange.

Although i don't recommend doing what i did, he's still in tolerance.

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what's he chancing? tight valves don't lead to catostrophic engine failure, just sometimes harder starting and if they go to zero a burned valve....maybe.

I was at .002 when I shimmed recently. I checked them 20 hrs previously and you could barely get an .004 in...meaning just under tolerance. I shimmed them when I noticed my WFO, hi rpm, jetting was getting a little strange.

Although i don't recommend doing what i did, he's still in tolerance.

I'm pretty sure they have some reason why they would want you to adjust the range. because you disrespect your bike, doesn't mean you should tell people to do the same. and yes, what your doing is called "ABUSE" by the manufacturer.

I say, do what the manual tells you, there is a reason for every maintenance in there to keep your bike the best it can be. and in best overall running condition.

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I did my last night, watch out for the cam clips! I had to remove the left cover to retrieve it. :thumbsup:

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I had the same concern late last fall when some of my valve clearances were at the recommended minimum. I've been out riding ~ 8 or 9 times since and have re-checked my valves every two or three hard rides. So far, are all still within spec. By checking them often, I'm less concerned about "them going out of spec after just one ride".

FYI: I'm an intermediate rider 50/50 track-n-trail.

I.E. I do not ride WO and test the rev limiter on a daily basis.

Unless you race or ride WO, I agree with hrpufinstuff. You're OK for now just re-check the clearances a few times through out the year, and keep that oil & filter clean. By all means if you just happen to have the correct shims at hand, go ahead and adjust.

Another point... the OEM pads you'll remove will measure in 0.01 increments 181, 183, 185. Replacements OEM pads are sold in 0.05 increments 175, 180, 185. This means if you’re not exactly at the minimum clearance, shimming with a new pad that is ".05 larger", will put you out of spec (too loose). So you may want to do as I did and pull the buckets at your next check and record the sizes. When it's time you'll have all the info you need to order only the ones you need. Found that I can swap pads around to the point that I only need to order two 175 to put al valves back in spec. (definitely cheaper than the $70-80 shim kit).

Note that someone here on TT stated that it’s better to be .01 tight vs. being .01 loose.

jp

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He is in spec, so why shim? These YZ's like to run on the tight side, so I bet that is where they were set from the factory.

Your fine, just check them every 15-20 hours like stated.

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He is in spec, so why shim? These YZ's like to run on the tight side, so I bet that is where they were set from the factory.

Your fine, just check them every 15-20 hours like stated.

is that mm or thousands of an inch?

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4 year old thread............

I kind of miss WR250Captain. That guy would argue with anyone about anything. Here he's telling me I abused and disrespected my bike.

He argued all the time. He was 19 years old and always spouting off his knowledge. He kept "the pot stirred"!!!!

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4 year old thread............ I kind of miss WR250Captain. That guy would argue with anyone about anything. Here he's telling me I abused and disrespected my bike. He argued all the time. He was 19 years old and always spouting off his knowledge. He kept "the pot stirred"!!!!

Ha ha you sucked me in. Glad I read the whole thread. I was about to post in your defense! I always run my valves a little closer to the tight side. :smirk:

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