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View Full Version : CRF250R valves replace?



Jebus
1st May 2012, 20:05
Hey,

Just doing the first rebuild on my bike, 08 CRf250R, Approx 70 hours, piston, bore, everything looks good.

It was pretty hard to cold start before doing this. Before I pulled the head off this evening i checked the valve clearances and the intake and exhaust were a bit tight.

Intake and exhaust were both approx 0.05mm too tight. Factory limit is 0.03 I think. Was hard to measure as my feeler gauges didnt have enough sizes, but they were definately a bit tight.

I have attached a pic of the underside, there is a small bit of stuff leaking through the valves, I havnt put any liquid behind them, its just left over oil etc.

Do these valves need replacing? If so what recommended and who do cut the seats etc, ive read its pretty tricky? Or can I get away with smaller shims for a bit longer? Id perfer not to have to do new valves at the moment if I can.

Thanks!!

263011

barty5
1st May 2012, 21:37
you should be able to have them re shimmed take complete head to shop and have done shouldn't cost to much to do that way be careful heard guy say the other day that a shop told him it couldn't be done with out the complete bike (load a bollocks) just a shop money hunting.

Jebus
1st May 2012, 22:02
Yeh definately, Whos the best to go to for this? Will Mrmotorcycles do it? wrong colour!

scott411
2nd May 2012, 08:00
Yeh definately, Whos the best to go to for this? Will Mrmotorcycles do it? wrong colour!

they will do it,

Jebus
2nd May 2012, 12:57
Ended up getting the shims done with Brent and Spectrum in Takapuna, was really good service, super fast and did a great job.

Recommended, thanks!

meteor
2nd May 2012, 17:28
Im just about to to the top end on my 08 CRF250R for the first time. I've heard that reshimming is just a temp fix and won't delay getting new valves by too long???
Also if I do the valves it makes sense to go stainless... It's done 120 hrs.

barty5
2nd May 2012, 20:28
Im just about to to the top end on my 08 CRF250R for the first time. I've heard that reshimming is just a temp fix and won't delay getting new valves by too long???
Also if I do the valves it makes sense to go stainless... It's done 120 hrs.

Yup go stainless but you will need to do the spring as well if you do. The idea behind not lasting to long depends on how much shit you give the bike with your right hand while riding but generally once they start to stretch they don't stop just depends on how long but no reason you wouldn't get a lot more hrs out of it unless of course they have already stretch way out.

CRF119
3rd May 2012, 20:08
Make sure you guys are taking care with your air filter cleaning and re oiling! Also remember to run grease around the edge of the air filter to help it seal. (You can buy proper grease) The reason i say this is most valves wear early on because of dust. Once they start going out of spec they can be re shimmed once after that your wasting your time and money.

meteor
4th May 2012, 13:46
Make sure you guys are taking care with your air filter cleaning and re oiling! Also remember to run grease around the edge of the air filter to help it seal. (You can buy proper grease) The reason i say this is most valves wear early on because of dust. Once they start going out of spec they can be re shimmed once after that your wasting your time and money.

I'm a bit of a nana trail rider on it and clean filter and airbox after every ride. I know it's a 'how long is a piece of string' sort of question but... If I was to get it shimed, how many hrs do you think I could get out of it before needing a valve job? Just weighing up if it's worth mucking around with shims or go straight to new stainless valves...
Bloody thing, wish I still had my XR!

barty5
4th May 2012, 14:57
I'm a bit of a nana trail rider on it and clean filter and airbox after every ride. I know it's a 'how long is a piece of string' sort of question but... If I was to get it shimed, how many hrs do you think I could get out of it before needing a valve job? Just weighing up if it's worth mucking around with shims or go straight to new stainless valves...
Bloody thing, wish I still had my XR!

yup it a bit a string when it gets hard to start youll know for sure.