[buddyguest]

Hi all, new to the CRF world. Just bought a '07 CRF250R for my son and wow what a difference from what I am used to from the 90s. We bought it knowing there were issues starting, but once started it would run great. The bike sat for a while so I figured it would be a carb rebuild and cleaning to take care of it.

Ordered an All Balls rebuild kit for a 2007 CRF250R, received the parts and there are a few difference from the carb to the kit, one being the needle is a different length. Looking more at the carb and the manual, it looks like they went from an FCR01C in '06 to an FCR01D in '07. The carb on the bike is stamped with FCR O1CATH22.

Does anyone know if that means this carb is from an '06 and not the original '07 carb? Is this a valid swap, it looks like the jets and needles are different between the years in the manuals as well?

Anyone know how to order the correct rebuild kit based on the carb identification number?

Can you rebuild the different version of the FCR with the different needles / jets, etc to match the stock settings?

Any advice would be greatly appreciated

[JimDirt]

Welcome to the site !!

The person that should know is Leardriver ..... Hopefully he will chime in soon and give you the info you need , he is the resident carb guru , the only other person that might also know is Ken the owner , since he sells the parts , so he might have a insight to the meaning of the specific numbers and that it means if anything ...

You can try giving Leardriver a PM and hopefully he will reply quickly with a answer or at least guide you in the right direction ...

https://www.crfsonly.com/forum/memberli ... le&u=14707 (look where it says :PM: Send Private Message")

[Leardriver]

Welcome.

FCR carbs changed from 2006 to 2007. The old O-ring mod that helped overcome a lean dead spot on the transition from the pilot to the needle circuits was improved, and the '07 and up carbs generally run great when they are clean.

I suspect plugged pilot jets first, and with a hesitation or bog down low, I suspect a plugged accelerator pump on a bike that has been sitting for a while. The fuel storage area cast into the bottom of the float bowl gets gummed up. It's easy to test by looking in the back of the carb while you whack the gas quickly, and watch for a big fat stream of gas to go squirting forward. The hard part is visualizing it, and swinging the subframe up out of the way is the easiest way to see, with the penalty of having to put it back together. With practice, this is a 15 minute job start to finish.

You don't need a rebuild kit, just a new pilot jet and the right main jet for your altitude. The factory needle works great.

A 172 main jet seems to be the consensus at sea level, a 170 at 2,000 feet elevation.

[buddyguest]

Thank you so much Leardriver and JimDirt! We will take a look and see what we find. You guys are awesome, glad I came across the site.

Welcome.

FCR carbs changed from 2006 to 2007. The old O-ring mod that helped overcome a lean dead spot on the transition from the pilot to the needle circuits was improved, and the '07 and up carbs generally run great when they are clean.

I suspect plugged pilot jets first, and with a hesitation or bog down low, I suspect a plugged accelerator pump on a bike that has been sitting for a while. The fuel storage area cast into the bottom of the float bowl gets gummed up. It's easy to test by looking in the back of the carb while you whack the gas quickly, and watch for a big fat stream of gas to go squirting forward. The hard part is visualizing it, and swinging the subframe up out of the way is the easiest way to see, with the penalty of having to put it back together. With practice, this is a 15 minute job start to finish.

You don't need a rebuild kit, just a new pilot jet and the right main jet for your altitude. The factory needle works great.

A 172 main jet seems to be the consensus at sea level, a 170 at 2,000 feet elevation.

[Back2-2]

It is very probable that you have a late build 2006 that received a 2007 carburetor.
As for rebuild, there are three o-rings on the fuel inlet fitting that dry and and can leak. There is also a float needle that the tip becomes dry and forms a groove [ring] around the seal area where is seals in the seat. Those two items are the usual areas that need to be rebuilt / replaced. Other than clogged jets. Do not use carb cleaner on the rubber floating valve seal as it will damage it.
If you have questions on the rebuild kit that does not seem to be for your carb. Call All Balls, they have been very helpful over the years on bearing questions I have had and suspect they would be for carb kits also.