tuning FCR carb

[stalefish_132]

I'm not quite sure that i have my FCR39mm set up exactly right, mods include wiseco 11:1 89mm, hot cams stg. 2 (old), full exhaust and no air box lid with UNI filter.

my jetting is
188 main
52 pilot
needle set on lowset setting
not quite sure on the air/fuel screw.

my elevation is 1500ft to 5500ft but for the most part its 1500ft to 2500ft.

generally temps between 68*F to 86*F but moastly around 72*ish.

i know this is quite a wide temp. and elevation range but what i'm mostly after is tips on ajusting the air fuel screw. i've serched aroudn and havn't really foudn what i'm looking for, i think i'm running a little lean on the pilot and maybe a bit rich on the main, my plug looks like a darkish brown. any FCR guru's kicking around?

[GPracer2500]

This should help you get your fuel screw and pilot jet sorted: http://www.exriders.com/vbb/showthread.php?s=&threadid=229923.

[zrpilot]

I think you are right, that main is a little big considering you altitude. A 188 at 2500 feet would equate to a 192 a sea level. And when you say the needle clip is on the lowest setting, is that closet to the tapered tip or the other end?

Lastly how does it run?

[stalefish_132]

thanks GP.

it runs awesome, the needle is set at the richest setting ( lowest on the needle) i did have a 185 main in it then i did some air box mods and went up a size just to be safe and haven't really taken the tiem ot get it really dialed in. right now its cooler out so i've been runnign it with a closed air box lid just to be safe but as it gets warmewr out i'll start playing with it

[speedfreaksguy]

That 52 pilot seems too big. I tune FCR's all day for CRF250 and 450 bikes. Rarely do I need to go bigger than a 45 pilot. Is this a YFZ carb. If so, look into blocking the ACV. The air cut valve. It makes tuning the pilot circuit really difficult on that carb.