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05-07 squish problem

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I have a 2006 cr250 and i just fully rebuilt the engine . I am having detonation problems on the top end . When i rebuilt i noticed the head was in bad shape it was pitted up . I have been reading up on the squish clearance issues with these bikes what i was wondering was id there a place i can buy a head with the proper squish band or do i need to buy a new one from honda , measure my clearance then send it out to be fixed:/ ?

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as soon as you hear a noise like gravel or marbles hitting your exhaust pipe, thats detonation, you immediatly stop riding till the problem is rectified. if it's making that noise in the middle throttle position, which is where it usually is, then you move the needle clip down one position to raise the needle a little.

 

eric gorr has heads made up already, just call him. it's like 70 bucks and a new head is 80 so it's a good deal. the pitting is definatly from your detonation problem.

 

I have a 2006 as well, i messed with the needle position to lean the needle and heard the detonation, i stopped riding and put the needle back the way it was, never heard the detonation again on 93 pump gas.

Edited by Atieri

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RB Designs also does machine work on the cyl. heads & has a good reputation on this website.   If you click on the link it has his info & a how to section on how to check the squishband.    http://us.yhs4.search.yahoo.com/r/_ylt=A0oGdNuEZjlS1ikA0iQPxQt.;_ylu=X3oDMTByZWgwN285BHNlYwNzcgRwb3MDMQRjb2xvA3NrMQR2dGlkAw--/SIG=11an3ugps/EXP=1379522308/**http%3a//rb-designs.com/

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Thanks H4L but i was already reading up on his work , the issue is my heads pitted up and i wasn't sire if he could fix it , hoping i could buy one with the proper squish band

How do i reach eric gorr?

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I know you said you fully rebuilt your motor, was that a full rebuild including crank seals? Have you checked for air leaks? Could also be from running to low of an octane gas, maybe while riding a sand track?While the squish is off I haven't had one of these detonate to that extreme. Not saying it couldn't happen but the case reed is bullet proof!

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Both can fix the pitting. It is removed when they mill the squish and dome to the proper shape.

RB did my son's KDX 220 head. His work, cost and turn around time was great. He did the work and shipped the head back to the same day he received the part.

Edited by Kirkes

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The bike did the exact same thing before i rebuilt , new crank seals and bearing . I am running 91 oct thats the most i can get where i live .

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I have been reading up on the squish clearance issues with these bikes .....measure my clearance then send it out to be fixed:/ ?

RB Designs does excellent machine work- very precise, with a high level of attention to detail, and quick turnaround times.

I have previously had cylinder head machine work performed by Gorr, Pro Circuit, and RB Designs. Of the 3, the best results were with RB Designs.

Call or e-mail RB for an evaluation of the condition of your head prior to shipping it. He also has complete squish measurement instructions on his website which must be followed.

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Just Call RB like everyone says, most likely he can fix the oem head while at the same time correct the squish band

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Thats what happend to my crank the rod bearing went , just before it went i was getting this clicking sound in mid range in the higher gears . After a full rebuild its still doing it . Can the head in this condition be my problem ? Or is it det, and the pitting has no effect on the sound ?

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Either way i cant run it like this question is a new one or send this one to rb. I am waiting to hear back from rob to see if its fixable

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If my stock squish is .080 ( just for example ) and i need .050 wont milling the head make the gap bigger or do they mill down the outer edge where the gasket sits?

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If my stock squish is .080 ( just for example ) and i need .050 wont milling the head make the gap bigger or do they mill down the outer edge where the gasket sits?

 

 

he mills down the outside and than reshapes the bowl for whatever fuel you would like.  Can rb fix it did you call?

 

and yes a new head is crap for squish as well and would need tobe machined.

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But if i buy a oem head the squish will still be off wont it?

 

yeah, but it won't be all f'd up from stray rod bearing.

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