09 Carb on 05

Having issues with my crf250x 2005 Carb.

The hot start was completely stuck and now with the new one it does not slide in & out. Where the hot start is located it seems that the walls inside are rather rough. To me this does not seem normal.

I have found a used 2009 CRF250X Carb but not sure if it will work on my 2005??

Any input would be greatly appreciated.

I believe they have not changed the carb enough for this not to work. In 08 (?) they changed the pilot screw and the AP linkage, but the body and diameter are the same.

im not positive yet as i havent measured them but i believe the 05 is a 37mm and the newerone is 40mm waiting to hear back on this site in another post i think it will be a good swap if true.

yup its true the x has a 37mm carb on the older ones for sure and the newer r have a 40mm.

should be a good swap.

Edited by lilman

Thanks lilman

But if I go from 37mm to 40mm will my air boot and the rubber boot from carb to enjine connect to the the 09 Carb?

im not home to measure but i assume the only change would be to the id of it

i could be wrong but i think back in the old days when you bought a bigger carb the bigger part is the slide part of the carb the boots should be the same size...i could be talking out of my ass though

i agree, its the i d that prob changed, just bored 3 mm probably

correct me if I am wrong, but the X carb never changed. The R carb has been bigger since 06.

I rec'd an email from James Dean (JD Jetting) and he has tested a 250R carb that does have a 40mm manifold on it. A 250x has a 37mm manifold.

Per his email....

"I had installed a 40mm carb on a 2004 CRF250R, which originally had a carb like your 37mm version, as a test to see how the motor would perform. This change is OPPOSITE of what most 2006-2009 CRF250R owners were usually making when the CRF250R went to the bigger carbs. Many of the newer CRF250R's developed a bog when using the bigger carb. The top-end power gain was not enough to offset the low-end issues, and slightly less low-end response."

2009 X still has a 37mm carb, but you can probably save your carb. The Bore walls of the hotstart are not real critical as long as the plunger seals on the end. You could polish the bore and put the plunger back in with a little grease or anti seize. Use it more often to keep it , and the cable free.

Having issues with my crf250x 2005 Carb.

The hot start was completely stuck and now with the new one it does not slide in & out. Where the hot start is located it seems that the walls inside are rather rough. To me this does not seem normal.

I have found a used 2009 CRF250X Carb but not sure if it will work on my 2005??

Any input would be greatly appreciated.

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