suggestions on jetting 400 carb

[Redhotrod]

Hey guys,
need some suggestions on what size main keihen jet to go with, my bike is a 1997 300ex, bored recently(not sure how much) full white bros exhaust, no airlid and K&N filter with outerwear in stock box and got a 400ex carb, I am in northeast ohio at 812 ft to sea level and the temp lately has been around 50*F

[cheatermtrsprts]

I live in Florida not too far above sea level. Maybe a couple hundred feet. My step son rides a 98 300 with 11.25 to 1, web 254 cam and TC exhaust. We also have the 400 carb. We are using a 38 pilot and a 138 main. It is a little rich. I think you would have to run a 42 pilot and somewhere around a 140-145 main jet. This should get you pretty close! It will be a good starting point. Good Luck

[Redhotrod]

thanks for the advise, I will let you know how it works out.

[Redhotrod]

Well, ended up running best with a #142 main, #38 pilot and the needle "E" clip on the third notch down. What a difference it makes having the right jets in there!:D

[cheatermtrsprts]

Glad it worked out! Have fun!!