Hey everyone, im new to the forum but ive been reading the members questions and replies for a year or two now., ANYWAYS....it goes like this... I have a 99 440ex with a 12.3:1 piston, mild porting/polishing, full R4 exhaust, a K&N with no lid, and im running all of this through a stock carb (<--- ouch, i know), BUT the thing has never been correctly jetted and nobody that i've talked to has seemed to help at all. If anyone has a setup like this, or knows something about what it will need, your help is greatly appreciated!

 

what elevation you located at? what temperatures you ride in?

 

165-170 main jet and a 40 pilot should be close enough mto ride it safely.

 

its avg about 70 degrees and we are at about 1000 feet above sea level.....you guys give me a repply like "165-170 main and a 40 pilot" isnt that a pretty big range? how about the needle taper? needle clip position? slide cutaway? how much does all of this come into play....what ive read and learned has told me there are many more things to worry about than just main and pilot jets.....does anyone have a jetting "calculator"? or know about one? please help!!

 

There isn't a main between 165-170 that I know of. If that seams like to big of a range you are way more in to jetting then I am. The stock pilot jet is a 38 so going to a 40 isn't a big swap. There is other needles for the carb but, I have used one on a 400.

 

i would try a keihin 165 main, stock needle with clip in 4th position from top, 45 pilot jet, 2.75 turns out from lightly seated.