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CRF head reconditioning

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Hey guys,

Looking for some recommendations on where to send my head for kibblewhite valve replacement, valve seat cutting, etc. Also, what should I expect to pay for this service?

My bike is an '04 crf 250x, has all the free mods plus the R header, exhaust, and '05 cam. Other than a few shim replacements on the intakes it has been problem free.

If I send out the head, what can I expect for work needed on the piston and cylinder? Is this something that I can do myself or will I need to find a local shop?

Thanks and Merry Christmas.

Steve

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Do it yourself. Removing the head is the toughest part of the job. A set of KW valves and springs cost around $150-ish. Having the seats touched up costs around $60.

Assembling is pretty easy. A valve spring compressor is usually next to free at an auto parts store. They loan or rent them.

Once you do this yourself, you will never pay someone again.

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+1:thumbsup:Think haw many hours you have on the piston and maybe change also.High comp cosworth piston is my next:smirk:

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I am in the same boat. I need to do the same thing. there was a thread sometime back that talked about just replacing the head with the 2007 head that had a better setup. Seems like the price of that was about the same as sending it out to have someone redo it.

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Kind of depends on what you want or need done to your current cyl head, and what you want to pay. Price range from low to high is roughly $60 to $100+. There are a few options in terms of whats available. Some shops use some expensive machines and cut more than the standard three angles into the seat trying to get the best flow and power, this will cost more.

The basic seat cutting job will include three cuts and match the seat to the face of the new valve. Also need to make sure the valve guides are in spec. The lowest priced seat cutting method would likely be done using a small hand held seat cutter capable of doing a good job if the guy knows what he's doing and has good tooling. But not every machine shop is geared to do small engine head work so in that sense you gotta kinda watch out. Hope that helps.

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Send it off to mxtime.com along with your new valves and he will re-cut the seats and install the valves. I think its 80 or 90 dollars to do it.

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Thanks guys for the feedback. Not sure I want to do it myself, but I need to give it some more thought. The most work I have done to the bike is re-shim and replace the cam, this sounds a little more involved.

I figured I would need to replace the piston and rings. Any suggestions on what piston to use with my current setup? Is this an easy job to do once the head is off?

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Thanks guys for the feedback. Not sure I want to do it myself, but I need to give it some more thought. The most work I have done to the bike is re-shim and replace the cam, this sounds a little more involved.

I figured I would need to replace the piston and rings. Any suggestions on what piston to use with my current setup? Is this an easy job to do once the head is off?

High comp piston and run fine on pump fuel:thumbsup:Adds some more punch to the bottom end.If you can change a cam and time the motor then you van take apart and build the top end easy.Little tip if you do it yourself,Tie some welding wire through the cam chain keep it tight.Once you pulled the topend over the chain tie the welding wire to the frame:thumbsup:

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High comp piston and run fine on pump fuel:thumbsup:Adds some more punch to the bottom end.If you can change a cam and time the motor then you van take apart and build the top end easy.Little tip if you do it yourself,Tie some welding wire through the cam chain keep it tight.Once you pulled the topend over the chain tie the welding wire to the frame:thumbsup:

I wanted to put a new top end in my bike soon just to go ahead and get it done before it goes out.. Can i put a high compression piston kit in it without changing anything? And what is the diff in a high comp piston and a reg piston? What does it do for the bike and is it worth the extra money?? How much is it normally to get a new top end kit installed on one of these new thumpers?

Last time I got a new top end was on my 89 rm125 back when I was 15, so about 17 yrs ago and it was $150 total... I'm sure pricing has come a long way since then, and from 2stroke to 4stroke :bonk:

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Does anyone know if I can run a '08 250R piston with my current setup ('04 250x head w/ '05 250R cam)?

Thanks again.

yes you can. it will bump up the compression to 13.1 to 1. that's what i run its cheaper then an aftermarket. i just got 150 hours on mile could have gone longer

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yes you can. it will bump up the compression to 13.1 to 1. that's what i run its cheaper then an aftermarket. i just got 150 hours on mile could have gone longer

Got it, thanks! :bonk:

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I wanted to put a new top end in my bike soon just to go ahead and get it done before it goes out.. Can i put a high compression piston kit in it without changing anything? And what is the diff in a high comp piston and a reg piston? What does it do for the bike and is it worth the extra money?? How much is it normally to get a new top end kit installed on one of these new thumpers?

Last time I got a new top end was on my 89 rm125 back when I was 15, so about 17 yrs ago and it was $150 total... I'm sure pricing has come a long way since then, and from 2stroke to 4stroke :bonk:

Hi bro,adds alittle bottom end hit and 13.5.1 runs fine on the uk pump fuel:thumbsup:I fitt my own pistons myself,aint hard so sure you could do it urself.Dont need to change anything in your set up to run a high comp piston.Also over here it costs nearly the same to get a honda piston as a high comp.Im always on the search for alittle morehit for a few bucks:smirk:

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Hi bro,adds alittle bottom end hit and 13.5.1 runs fine on the uk pump fuel:thumbsup:I fitt my own pistons myself,aint hard so sure you could do it urself.Dont need to change anything in your set up to run a high comp piston.Also over here it costs nearly the same to get a honda piston as a high comp.Im always on the search for alittle morehit for a few bucks:smirk:

I know you are my friend. I'm sure your bike runs as badass as it looks, your bike is "The One":worthy:

:bonk:

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I know you are my friend. I'm sure your bike runs as badass as it looks, your bike is "The One":worthy:

:bonk:

The only one im gonna f.cking buy:lol:Im moveing back up to a 450r in few months.Just need to work on my hand and leg grip:smirk:Got a friend i ride with on a o7 450r and im sick of him being able to keep up on open parts of some tracks we ride.As you no to be quick on a 250 4 banger you got to ride it like you stole it on a mx track.My rideing aint half improved since going to a 250,so a 450r should really up my game on track:smirk:

I hope:busted:

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