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Need help w/ jetting an 04 crf250r

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I'm trying to figure out what to do with the jetting on my dad's 04 crf250r. Whenever I give it 3/4 throttle or more it completely cuts out and almost stalls out. I noticed this after the valves were properly adjusted, so I don't think it's the valves. The bike has an fmf slip-on silencer, stock header, and stock air filter. The altitude where I ride is in the 800 ft range. I would like to go ahead and set it up for this summer, since the bike is hardly ever ridden in cold weather, if at all, so the air temp would be around 80 degrees. What kind of jet sizes would you guys recommend for these conditions? Any help would greatly be appreciated. :thumbsup:

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Jetting for 80 degree temperatures when it's 20 degrees now isn't going to be easy. From my understanding there are some jetting calculator's that will help get you close however, perfect jetting will come from trial and error during 80 degree days.

JD Jetting would be a good place to call if you're not "experienced" in jetting. If you buy their jetting solutions (around $75.00) they seem to be able to calculate variables like this as well as many others. Plus, personal "one-on-one" service and usually spot on jetting advise is only a phone call away.

Check out this thread: http://www.thumpertalk.com/forum/showthread.php?t=872855

Within this thread are some great "step-by-step" instructions for jetting/setting up your FCR carb. GET THE PDF, TOO!! I started this thread several weeks ago and was fortunate enough to have attract William1 to the thread. Trust me, you'll find many of the answers your looking for within this thread.

Hope that helps, bro!!

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Thanks for the post. I've never been into a modern 4T carb before so trying to figure this stuff out can be a daunting task. This is for my dad's bike, I have a 2T, so the jetting doesn't need to be spot on since he isn't an aggressive rider at all. But when I got on the bike and it bogged like it did it really bothered me lol. I'd like to know what setup other people are running in similar conditions?

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