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Is life with the big CRF better ?

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Posted by: oldfrt613---------------------

Our CRF250 is requirinng valve adjustments at a little over 15 hrs ( 5 hrs before recommended ). What kind of service intravals are you guys seeing on the 450 ? What kind of intravals are you guys running Kibblewhites seeing ?


Posted by: rickyd---------------------

SO far i have 12 hours on my 06 450, first kick starts.. It was reccomended too me too check them at 30 hours for my riding style (not bouncing it off the rev limiter)


Posted by: cthowards---------------------

I bought a used 2005 CRF450 with 43 hours on it. It was raced a few times by a 35+ vet novice rider. I checked the valves at 43 hours and they were all right on spec. The 450 can be lugged and does not need to be revved out so based on my riding style, I am expecting to not have to do any major work for awhile on the top end or valve train. I will still continue to check the valves every 15 hours as recomended in the service manual, change the oil, etc..


Posted by: 06crf450r---------------------

i love my 06 450, i haven't had any problems yet except user error! starts first kick every time but keep a constant eye on things as it is a thumper and they do vibrate and things tend to get loose after time like my plastics i cant keep them tight to the frame as far as my valves go i hadn't had any problems yet but will keep you posted as i ride it more!!! and defentily keep us posted if you find anything out on your 250


Posted by: CRF450XRIDER---------------------

Got An 05 450x Model,i Prefer It Over The 250x Just Because You Don't Have To Rev It.


Posted by: wetrat---------------------

factory book says 15hrs or 7.5 for compatition @ 20 mine are fine


Posted by: bigred455---------------------

Not a CRF,but I have 450,RMZ a little over 120hrs,valves stayed exactly the same I check every 10hrs. My first check was at the 3hr mark and they have not budged. It is not unheard of to shim at the 15 hr mark,as long as you got them before they hit 0. You may not have to touch them for who know's how long,at the factory they could of been on the tight side leaving.Is this the first time checking? What were your readings?


Posted by: john3_16---------------------

Quote:
Originally Posted by bigred455
Not a CRF,but I have 450,RMZ a little over 120hrs,valves stayed exactly the same I check every 10hrs. My first check was at the 3hr mark and they have not budged. It is not unheard of to shim at the 15 hr mark,as long as you got them before they hit 0. You may not have to touch them for who know's how long,at the factory they could of been on the tight side leaving.Is this the first time checking? What were your readings?



That's impressive...what year ?


Posted by: bigred455---------------------

Quote:
Originally Posted by john3_16
That's impressive...what year ?



Thanks, it is a 2005.


Posted by: RMZRIDER---------------------

Quote:
Originally Posted by bigred455
Not a CRF,but I have 450,RMZ a little over 120hrs,valves stayed exactly the same I check every 10hrs. My first check was at the 3hr mark and they have not budged. It is not unheard of to shim at the 15 hr mark,as long as you got them before they hit 0. You may not have to touch them for who know's how long,at the factory they could of been on the tight side leaving.Is this the first time checking? What were your readings?



I totally agree on the rmz's, everyone complains on lack of quality yet my valves are still to spec at around 60 hrs and have had no problems with the bike at all


Posted by: Britt Boyette---------------------

I know they say to replace the valves when they go to Zero but, what do they normally run. I'm right at .006 on my 03 CRF 450R. Also, do the exhaust valves seem to wear quicker than the intakes or is it the other way around?


Posted by: Rich Rohrich---------------------

Quote:
Originally Posted by Britt Boyette
I know they say to replace the valves when they go to Zero but, what do they normally run. I'm right at .006 on my 03 CRF 450R. Also, do the exhaust valves seem to wear quicker than the intakes or is it the other way around?


Honda OEM intake valves are about $50 each, valve springs are about $7 each (yes the springs need to be replaced along with the valves every time )

The OEM exhaust valves don't suffer the save face recession issues as the intake valves, but when guys run pump gas the deposits left behind will erode the exhaust valve face and destroy the seal. The exhaust valves are steel and the face can be re-ground with the proper equipment, but if the erosino is bad enough (very common) then the margin on the end of the valve will be too small and the valve will be unusable. It's easier to just replace the exhaust valves in most cases.

For most guys changing over to Kibblewhite stainless valves and their spring kit is the best solution for long term reliability, and ease of maintenance over the life of the engine.

No matter what valves you use, if you have a couple of seasons on the engine it will need a valve job and you'll also need to carefully check the exhaust guides for wear. Excessive wear in the bottom third of the exhaust guides is a common problem due to the high ratio roller rocker Honda used. You also need to look closely at the roller itself for excessive wear.



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