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i need specifics! jetting

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I have a 2001 Honda CR250R with a pro circuit platinum pipe, jetting is 400 main jet with the stock needle and a 30 pilot jet A/F screw is 2 turns out and clip position is one above the middle position. i am at 2400 feet elevation and i am running a 40:1 fully synthetic ratio. my plug is wet and gas/oily. bottom end is weak mid is great and not much top end. the bike used to run great when i bought it with the gas that was in it but now i changed my oil ratio it runs sluggish on bottom but before it would rip bottom and mid just like i wanted. any specific jetting issues i should fix? im thinking main needs to come down a size?

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Get the J.D. Jet kit...easy to do...it will fix all your jetting problems and will make your bike rip...I was hesitant but I finally caved in and got one and i should have done it sooner

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sounds like he had some race fuel in it. I had a cr250 2005 with alot of mods done to it. cylinder decked, head work, porting and with race fuel it would jet good and run clean but when i went to just pump gas it would be very rich and foul plugs quickly.

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Why did you change your ratio if it ran good before? You shouldn't change your ratio without also adjusting your jetting.

well because he had it jetted to run 50:1 and from what i have been told that can cause major crank problems because of the lack of lubrication. I dont know for sure but everyone says something different but i would rather have more oil rather than not enough. and i know i shouldnt change my ratio without re-jetting, thats why i am asking which way to go with the jetting. I'm new to the 2-strokes so the whole jetting/oil ratio is getting confusing. im used to thumpers where you go to a bigger jet size if you need more fuel but now i am so confused with what oil ratio goes best with what jet sizes and it is getting overwhelming. there are so many variables with 2T. :thumbsup:

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Right about now, with the temps increasing 20 degs hotter everywhere, it's not unusual to see the bikes run overly rich. YOu can't really go w/ the same jetting that you've had back in the fall. At the very least, the needle's clip needs to be raised one notch up to lean the 1/4-5/8 throttle circuits. Sometimes, even a pilot size change might be necessary.

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2001, at sea level my friend runs

27.5 pilot

stock needle, 1st clip

s7 nozzle

390-400 main

youre higher up so it wouldnt surprise me if you need to go leaner that what is currently in your bike. we run yamalube 2r 32:1 with temps last weekend at 60-78. the s7 nozzle made a big change (when it was first changed way back) as well as moving the needle up to full lean (i recommended he try it and he was stoked with the improved response). strictly desert riding here.

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2001, at sea level my friend runs

27.5 pilot

stock needle, 1st clip

s7 nozzle

390-400 main

youre higher up so it wouldnt surprise me if you need to go leaner that what is currently in your bike. we run yamalube 2r 32:1 with temps last weekend at 60-78. the s7 nozzle made a big change (when it was first changed way back) as well as moving the needle up to full lean (i recommended he try it and he was stoked with the improved response). strictly desert riding here.

cool, because it is leaner jetting for higher altitude if i am not mistaken? and yeah, lots of serious trails here! desert would be fun, too bad there is nothing like that for 1000's of miles from here hahah :thumbsup:

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