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View Full Version : 39mm needle adjustment?


bighig
07-13-2003, 05:23 PM
Looking at fine tuning the fcr carb. How do you adjust the needle?Do you take off the top of the carb? Justr installed that billet air screw and it needs to pull alittle harder on top end. Gotta get a new plug also so I can judge the color.
jgfarmsracer
07-13-2003, 05:50 PM
what main jet you runnin
mbiigambler
07-14-2003, 04:31 AM
Yep, take the cap off and I use tweezers to pull the needle out, and adjust the clip accordingly. Sounds like you'll want to try by moving the clip down one notch and see how the bike runs.
bighig
07-14-2003, 07:24 PM
I have a 440. 165 main-52 pilot air screw I think is 2 turns out.
jgfarmsracer
07-16-2003, 01:45 PM
i have a 440 with 180 main, no needle ajustments at all

If you are not having prob's with the mid range don't mess with the needle start puttin biggger main's in, when it cuts out at top end
Dave400ex
07-16-2003, 05:48 PM
I bought a FCR 39 off of Sparks425ex, and was wondering how hard it was to get dialed in, and then if it's really sensitive and needs to be re-jetted a lot? Right now my stock carb is jetted for year round and starts fine in the cold winter. I don't really know how to jet, so I was wondering if the FCR could be setup like my stock carb, or if it will need to be jetted a lot? Thanks...
bighig
07-16-2003, 08:00 PM
So keep going up on the main jet until it pulls really hard on top end? I will be going richer rite?
jgfarmsracer
07-17-2003, 08:57 AM
Originally posted by Dave400ex
I bought a FCR 39 off of Sparks425ex, and was wondering how hard it was to get dialed in, and then if it's really sensitive and needs to be re-jetted a lot? Right now my stock carb is jetted for year round and starts fine in the cold winter. I don't really know how to jet, so I was wondering if the FCR could be setup like my stock carb, or if it will need to be jetted a lot? Thanks...

i never mess with mine during weather conitions just for different tracks (wide open fast or tight slow trees)

it's not as weather prone as a 2-stroker
mbiigambler
07-17-2003, 09:13 AM
hey jgfarmsracer,
what do adjustments do you do for the differrent riding conditions?
jgfarmsracer
07-17-2003, 12:36 PM
i will drop 2 to 3 main jet sizes for the tight tracks(like never gettin out of 3rd gear) , cause on them i never get it wound up to make the bigger main jets work properly and it will blacken or foul the plug
dpizz450
07-17-2003, 12:49 PM
:muscle:
jgfarmsracer
07-17-2003, 12:53 PM
Originally posted by YZrida
:muscle:

what does that mean lol lol