250ex performance carb swaps- everything you need to know!

[ryanh250ex]

OK kiddies i know some of you have been looking for ways to get your slow 250's up to speed. by doing a little bit of homework i found that a variety of carbs will mount up with NO major modifications to the 250....

Here's what bolts right up:
ATC200X carb- 24mm
XR200 carb- NON DUAL CARB YEARS ONLY- 26mm
DG aftermarket carbs for ATC200X/XR200- 27mm
Ebay 27mm carb for XR200/200X


with the bigger carbs you may find it necessary to switch to a twist throttle. for whatever reason the thumb throttles get stiff the bigger you go. you will need a new throttle assembly (should come with the carb) regardless.

obviously you'll need jets as well.

enjoy
-Ryan

[hillclimbingrec]

would i notice ANY perfomace gains if i got the atc??

[BlasterEaten250]

Good post. Which did you feel gave the best power gains? Would I be able to use the stock air boot and air box?

[ryanh250ex]

Originally posted by BlasterEaten250
Good post. Which did you feel gave the best power gains? Would I be able to use the stock air boot and air box?

I did not try any of them on but the ATC, i had the ATC carb around that an acquaintance of mine gave me to try, and it fit perfectly. By knowing that, i could deduct that those other carbs will fit, as they all work on a 200X.

I am not runing an airbox so I can't say for sure, but i do believe the ATC carb will fit.

[BlasterEaten250]

Did you ever run the new carb with the airbox? Is it a noticable power gain?

[ryanh250ex]

Originally posted by BlasterEaten250
Did you ever run the new carb with the airbox? Is it a noticable power gain?

No, I didn't. I was planning on it BUT because i had tuned the bike in the summer, and it is now wintertime (i.e. bike runs leaner now) and i'm already on the largest main jet i have, I did not bother . I also didn't want to swap what jets i had in my 250ex carb over into something that i'd end up getting rid of (the ATC carb, not the 250). I'm building my bike to rip on top end, so i'm holding out for either a XR200 26mm or a DG 27mm.

As far as performance gains i dont know. what your'e going to want is going to vary based on what kind of terrain you ride. i do alot of tight woods and open fields so i want something that has a killer midrange and sings up high. but ANYTHING bigger than factory is going to produce gains of some sort.

[BR16250]

Hey ryan can you tell me what jets you would run for the ATC.??? all i have is the stock 98 jet and a 100 in my carb now because because i got a pipe...im buying the atc

[ryanh250ex]

Check your PMs

[BR16250]

check yours