trying to tune a mikuni carb... help please

[cirame1]

Hi, i recently built my blaster and i been trying to tune my carb and i cant seem to get it right. i finally got it idling (kinda) but it revs up slightly as it warms which i read could maybe be to lean. the air fuel screw if im right is on the choke side of the carb is 1 and a half turns out and its a mikuni 28mm flat side carb. i have a fmf gold series exhaust and power core silencer and holes in my air box lid. im runing a 230 main jet and wonderin if maybe i need a bigger one. also i read that mikuni carbs jets are bigger or need to be bigger, any recommendations are appreciated thanks. also i have vito carbon flex reeds and a reed spacer if that matters... thanks

 

[blasternoob]

Is it reving good all the way through wide open throttle, like in 3rd or 4th gear? The stock 230 mainjet seems kinda small. What does your plug look like after riding for 20 minutes or so?

 

[b_russell_82]

Well here is what I have..... Stock 26mm carb and i'm bored .40 with the same exhaust as you and a KN filter and I'm at a 270 with the main jet... I would say go up at least that high. Maybe even a 280 since you have your air box lid off.

 

[cirame1]

yea plugs good after running for a while but i havnt had the chance to rip it around yet still working on a bunch of things but currently my masterlink is being stupid and it snapped so im trying to get my new one back on. The carb had a 200 in it and i bumpedit up wit a 230 and i have a 250 but i might try a 280 ish and def ride it around for a lil bit... thanks for the advise though.

 

[chadmann]

fmf suggests a 260 for use with their pipe

 

[rad-blaster230]

i think u might have a air leak maby like the one i just found on myne

 

[blasternoob]

Start out a lil fat, like 280? and fine tune from there. Spark plugs are cheaper and easier than rings, pistons and boring it out. I would also stick to 32:1.