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Fuel Screwed

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Sorry if this has been covered before but wasn't able to find it on a search.

I have a 2001 WR250, and while riding the other day my fuel screw rattled loose and fell out. The bike was a whole different animal, noticably stronger acceleration. So if I turn the screw out then it should go rich, but if it falls out would the vacum leak make it lean out. I ride at altitude so it's likely running rich normaly. Makes me wonder if the bike need to be a bit leaner? How much overlap is there with the circut contoled by the needle. Any advice is appreciated, thanks, joel-

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Direct quote from Eddies thread in the stickies at the top of this page.

how to confirm your pilot circuit setting

seems like the most common jetting issue that comes up are pilot circuit related.the following is a sure method to choose the needed changes.

with the bike warm and idleing turn the fuel screw in till the idle drops/misses.then go back out till the idle peaks/smooths.

this should happen between 1 and 2.5 turns on a fcr carb and 1 and 3 turns on a cv.

if you end up at less than 1 turn you need a smaller pilot jet.more than 2.5 (or 3 turns on a cv) you need a bigger pilot jet.

choose the appropriate size and retest.

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Sorry if this has been covered before but wasn't able to find it on a search.

I have a 2001 WR250, and while riding the other day my fuel screw rattled loose and fell out. The bike was a whole different animal, noticably stronger acceleration. So if I turn the screw out then it should go rich, but if it falls out would the vacum leak make it lean out. I ride at altitude so it's likely running rich normaly. Makes me wonder if the bike need to be a bit leaner? How much overlap is there with the circut contoled by the needle. Any advice is appreciated, thanks, joel-

Funny sometimes how you come onto a improvement with an unimprovment right?

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Yeah, I'm not to concerned about adjusting the pilot circut, that is pretty straight forward. I was wondering if the vacum leak caused by the screw missing would lean the bike out in the mid-throttle range. Anyhow, I raised the clip on the needle one notch and the bike is definitely running stronger so that vacum leak proabaly was leaning things out a bit.

thanks, joel-

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