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'04 crf 250r valve problem

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i have an '04 crf250r that one day would not start. only way to start it is like 40 kicks and using the hot start even when cold. using choke does nothing. i cleaned the whole carb out and it still isnt better. i was told it could be the valves. it runs fine once u get it running and will start pretty easy after. valve clearances were strange.

Intake, left .004 right tried a .0015 feeler gauge and it still would not fit in. and that is a .0015.

bad intake valve had a 182 shim

Exhaust, left .009 right .012

bad exhaust valve had a 255 shim

It seems that two valves are within spec and two are not with the intake one being way out. the dealer could not figure out the proper shim sizes and the shim calculator wasnt helping based on the shim sizes it listed.

ANyone know the shims i need to order? Are these valves shot? it seems that the intake valve is seriously stretched, this bike doesn't have that many hours on it. always well maintained. any help would be greatly appreciated, thanks, matt

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Have you owned the bike since new? If so and this is the first time the valves went out of spec I would reshim once then redo the top end after they zero out again.

If you bought it used I would do a top end just because.

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Same happened to me, just finished checking mine because it was hard to start today and they are tight, .002 wont go. this is the 3rd time now shimming, twice this year.

I have had the bike 2 yrs. since new. Are you saying I should do the top end and reshim or should I replace the valves, springs and do the top end?

Any advice much appreciated.

Grem.

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Well from what I hear, replace the valves and springs and shim to recommended specs. My valves havent completley zeroed on me yet but as soon as they do im gonna be looking to throw a high comp piston and possibly a 06 or 05 head on it with new valves. Just waiting to see if the 06 head will work with the 04 motors.

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i bought the bike and it had low hours, like it looked brand new and was ridden by an older guy who never got on the gas too much. I believe its the first time that its been checked. How do i figure out the shim sizes. when i use the shim calculator it shows me that the closest size it whats in there on the exhaust size, but the intake i cant even get a measurement on the intake one and i'd hate to buy a bunch of shims to get it to where i can measure it.

i can't just replace the valves that need it or do i have to replace them all along with all the springs? if i replace one valve do i have to buy new springs? and how do i find the shim size for the new valves?

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If you like the crf250 and plan on keeping it , or buying another one in the future. I would invest in a HotCams shim kit......I just got one for my 450 .

You will waste weeks trying to order the "right" shim. My valves were at zero , so I did a whole valve and spring job. My old stock shims did not work.

When you can't get in a feeler gauge , you just have to guess .

Hot Cams sells you 2 boxes of shims, with 3 different shims in increments of .05 ....like 1.80,1.85,1.90,1.95 ..........It is in 2 boxes and it looks like I would never need the 2nd box.....( it must be used in street bikes). So they sell you this kit like you are a professional mechanic , not a 1 bike owner.

I think honda should give you a box of them when they sell you the bike....just like the spoke wrench.

good luck

dp

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