trying to break in carb cant get it tuned right!!!

cirame1

New Member
Jul 30, 2008
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basically my quad sat for like a year and i finally got it running. i did fmf gold series full exhaust with silencer and a mikuni 28mm flat side carb. I have carbon reeds and reed spacer and my airbox lid removed. Bike starts right up and idles ok and warms up fine. Ive only rode it for about 5 minutes but it seems to be running good for sittign for so long. Bike has new oil and plug and air filter. I started jettin the carb and went form 230 to 250 to now a 280. the bike boggs on low throttle and then rips after a certain rpm and seems to do so in low geasr but havnt had chance to hit 4,5, or 6th gear. idk if its to rich or wat but my carb has 2 screws on it and one is on the choke side its big and gold and i have it about 1 and a half turns out and the other screw is on the other side near the back basically on the opening of the carb from the intake boot. plug is a lil dirty and im mixing 32:1. Def maybe think its bogging on throttle b/c its rich but i think a 280 jet is def. right with the fmf and no airbox lid. Any suggestions is appreciated thanks. Also idle is a lil weird itll idle for like 30 seconds and then wants to die unless you hit the throttle and then will idle for like 30 seconds but the bike has tors removed and after i rode it for like 5 minutes it was warm and idles good but low and steady. thanks
 
If your quad boggs at low throttle 0-1/4 you need to adjust the pilot jet. 1/4-3/4 is your needle and 3/4-wide open is your main jet. I'd suggest going down on your pilot if its bogging down low.
 
im not that good with the carb but i know the main jet but where is the pilot and whats it look like and wats a recommendation on a size???
 
The pilot jet should be somewhat close to the main jet. It a long skinny looking brass piece, that should take a flat screw driver to remove it. Hope this helps, its kinda hard to explain it. Take it out and see what size it is.
 
bump... im running rich and plug is dirty i dont think a 280 main jet is to big... how to tune my mikuni 28mm flat side carb??? and an approximate size for my pilot jet?
 
bumping main jet down to 270... dont know if its mucha of a dif. from 280 but we will see... also doing gear oil change and new plug...
 
I am running a 250 main and stock pilot w/ FMF Fatty, No air box lid and K&N. My blasty runs great. Did you by chance get fresh gas in her. Any gas that has been sitting for a year isn't going to be kind to a 2 stroke!
 
yup gas is 93 thats not even a week old mixed 32:1. i just put a new plug again... and i went down to a 270 jet. im gonna see how that runs and mayb go to a 260 jet if its still rich but i cant drive it b/c i have my rear shock out(installing 400ex) and my front wheels off(trying to break beed to flip wheels). ill let you know how it runs today though. also changing gear oil for the hell of it.
 
i think u need to move back to the 280 main and try moving the clip on the needle up 1 notch. then turn the lil screw on the side to acheive best throttle response