28mm (VM28SC) carbs plus mods.

i have a set of 28mm (VM28SC) and i am about to do a full rebuild on them. i have a vance and hines exhaust,k&n filters, accel 3ome coils with a dyna ignition, i know that this is the standard set up

Main Jet 112.5
Air Jet 1.0
Needle Jet O-8
Jet Needle 5J9-2 (last number is the clip position)
Throttle valve (slide) 1.5mm cutaway
Pilot Jet 17.5
Air Screw setting 1 1/4 turns out

is there any sugestions on setting up these carbs to run at full potential?

please can someone help me on this one? im lookig to know what would be the best jet setup for me? thanks out there.

How did it run before with these carbs? What did the plugs look like?

Do you have a local shop with a dyno? Best way to actually "see" the results of carb changes.

Post edited by: KZ_Rage, at: 2008/02/11 09:57

the bike ran but not well, the old owner was a ??? weeknd mecanic at best, the main jets that wer on her wer 15, the plugs looked fine, more lean than anything, iv replaced just about every thing, i would like to know if 18 would be ok as main jets? with the k&n, ignition,coil,leads and exhaust or will i go for smaller ones?

kzstreetfighter71 wrote:

the bike ran but not well, the old owner was a ??? weeknd mecanic at best, the main jets that wer on her wer 15, the plugs looked fine, more lean than anything, iv replaced just about every thing, i would like to know if 18 would be ok as main jets? with the k&n, ignition,coil,leads and exhaust or will i go for smaller ones?

Mains are 115's now and the pilots are 17.5's?

Is that V&H baffled or open?

As far as a bench setting to start out, 115's, 17.5's and the clip in the middle notch would be a good start. I'm still tweaking mine and I have a slightly opened MAC, pods, Dyna coils, std. elec. ign., 120's, 20's and middle clip, it might be a bit rich but I'm waiting for the weather to break so I can get a better idea.

When I get it where I'm close as I can get it by my methods then I'll take to Pro Stock here locally and have it dyno'd. Not trying to make it a hot setup right now, maybe when the day comes to take the head off but I'd like to know anyway.

i want to run it baffleless but to pass a safty in canada id better leave it on for now, i have new 115 on her now and 118 mains as spares and i have 17.5 and 20 pilots as spares, i think ill try the 115 first and see what she does but id like to think with all the mods and the fact they'r 28's i could up that a little?

Upping them won't hurt a thing as long as you keep a check on your plugs, they will tell you everything you want to know about your mixture once you get the ignition sound. Be sure to do a high speed check so you don't get gas fouled plugs at the furthest point from home right before it rains.. I believe they put that on the side of the little plug boxes now (or should!) :laugh: