air screw in or out??

[400exbiggun]

i promise this is the last carb question i will have...but untill i get my manual, will turning the air screw lean it out from about idle to around a little less than 3/5 throttle???
which way is lean, out ??

[F-16Guy]

On this particular carb, it's actually a "fuel" screw, it meters the amount of fuel introduced into the idle circuit. That being the case, turning the screw in will lean the mixture, and out will richen. That screw is really only effective from idle to about 1/8th throttle. If you're having trouble beyond that, try moving the clip on the needle up or down a spot.

[400exbiggun]

yeah thanks on clearing that up, it is good, but when i hit the throttle it like hestiates, and fires away, like slow response, i think it boggs a little too, but once you get to like 1/2 and above, it is fine. i thought that the needle was wrong, but i guess ya can't get around that.

[F-16Guy]

Your jetting sounds a little rich for a basically stock engine. Try putting your needle back to stock position and dropping in a 155. The 40 pilot is okay, but 160 sounds too big. I'm only running a 165 (dynajet) in my 416, and it has lots of mods.

[400exbiggun]

yeah, i was going out there now,
this might be a stupid question, but what kind of carb is in a kfx400 if you know?? if it is the same then would the dynojet mains fit??
cause i dont have the other jets, but my friend with kfx just got a kit:D

[400exbiggun]

ahh never mind, the carbs are different, i will switch the needle back down one position, and just leave the fuel screw right...

[F-16Guy]

Yeah, 2 1/4 to 2 1/2 turns out on the fuel screw, needle in stock position, and down a couple sizes on the main.