another carb problem please help... running rich..

[cirame1]

well i dont ride my blaster much but i recently did some upgrades and finally got it running and running pretty good. it has airbox lid removed and fmf exhaust. it has a mikuni 28mm flatside carb and i ended up going with a 28- main jet. bike was running rich and plug was black so i went to a 270. air fuel screw it set to 1 and a half turns and today i was bored so i took carb out to see where needleclip was set and i cannot understand how to move the clip or set iti didnt see any adjustments for it. so i ended up putting a 250 main jet in and a new plug to see how it runs. bike is bogging on low throttle. havnt checked out plug color from riding yet bc i only rode for about 2 minutes but even from warm its sputtering on 1/4 throttle in 1 and 2 gears. i think my main jet is fine idk if its the needle clip position or wat but it sputters real low and also on wot throttle so idk wat it could be... please help.

 

[cirame1]

the dif.in plug color from 280 to 270 was pretty good went from a black to a light black dark brown on the 270 so def. looking for another reason for bogging and sputtering. i also checked for air leaks definatly none. i thought about pilot jet but i was told not much is done to the bike for it to be the pilot and it should stay the same. looking for some answers tors is removes and has wires spliced on an 03' model and up. bike starts right up but idle is a lil off tried to die after about 20 seconds of good idle. looking into carb from airbox side and the middle peice is almost all the way down to the bottom... please any imput helps thanks

 

[quam]

well, you can increase your idle speed a little bit, that'll help keep her idling.
as far as the jetting is concerned, when you check the plug had the bike been at idle the last few combustions before you turned the bike off? if so then all you're reading is the jetting at the pilot circuit.
in order to see if you're main jet is correct, you need to run the bike at full throttle and make sure that the last combustion was at full throttle as you turn the bike off. don't let the engine pull down (no engine braking). then check the plug. this will tell you if your main jet is good.
after this, check again at mid throttle, this will tell you if your needle position is right. the way to adjust it is to pull the needle out of the carb and move the little E clip.

 

[cirame1]

yea i kno to check the main jet by running wot and thenpull clutch in and check plug. i was told to do this in all gears or can i do it in like 2nd wot b/ci dont have much room? as for checking needle position i do the same in middle throttle and shut off and check color also? for the clip i took the top off and i can pull out assembly with spring and middle piece where is the clip on the iside of the carb or under the spring in the middle? if thats confusing my bad im trying to picture my carb i just took it apart im thinking of where the e clip is...

 

[245stroker]

the clip is under the spring in the middle of the slide

 

[cirame1]

exactly wat i was wondering iight cool... i did touch that once wen i had to put a new throttle cable in so im a check today any other ideas on a warm sputtering at 1/4 throttle is a appreciated... thanks.

 

[cirame1]

oh and as i would understand there is 3 spots for the clip? and in which direction is lean and which is rich? would a bad spot for the clip cause a bad idle also? thanks

 

[cirame1]

well i took my carb off in search for the needle clip position but i took the top off the carb and compressed the spring. under was a plastic clip that i pulled out with needle nose pliers. there was no adjustments on it and under it was a metal piece where the throttle cable snaps on. the metal piece had 2 screws going downwars into the slide that held it in. so i seen no clip positions or ways to adjust it. took bike out for about 20 minutes mostly gears 1 2 and 3 and it feels good wen warmed i now have the 250 main jet in so i guess there isnt much more i can do. took plug out and it looks pretty good real light black and not wet. any help is appreciated i think im at sea level b/c im right near the ocean. airbox lid is removed and has fullfmf exhaust. bogs real light now not much trying to mess with nobson carb a bit... thanks