WHAT SIZE MAIN JET AND PILOT JET ARE STANDARD WITH THE BIKE

its running lean. Could be a vent problem with the gas tank. try running with the gas lid slightly open.. if this doesn't work increase the jet size in the carbs.

Here is specs for those carbs
- AISAN AS27VW
I.D. No. - 04A10
Bore - 27 mm
Idle r/min - 1300+/-100 r/min.
Fuel level - 9.0+/-0.5 mm
Float height - 20.5+/-1.0 mm
Main jet - #94
Main air jet - 1.2 mm
Jet needle - 5B10-3rd
Needle jet - 2.60 mm
Throtlle valve - 11.0
Pilot jet - #34
By-pass - 0.8,0.8,0.8 mm
Pilot outlet - 10.8 mm
Valve seat - 2.5 mm
Starter jet - GS1 #60, GS2 #54
Pilot screw - PRE-SET (2 turn out)
Pilot air jet - 1.35 mm
Throttle cable play - 0.5 - 1.0 mm
Choke cable play - 0.5 - 1.0 mm

Front cylinder carburetor:

·
112.5 Main Jet

·
17.5 Pilot Jet

·
(1) 0.020" thick shim washer under the needle

·
PMS setting apparently varies from bike to bike... but it should be 2.5 turns

Rear cylinder carburetor:

·
110 Main Jet

·
17.5 Pilot Jet

·
(1) 0.020" thick shim washer under the needle

·
PMS setting apparently varies from bike to bike... but it should be 2.5 turns

• Main Jet: 410
• Main Air Jet: 2.5
• Jet Needle: 6BFY43-74
• Needle Jet: S-1
• Pilot Air Jet 1: #40
• Pilot Outlet: 0.7
• Pilot Jet: 40

Out of curiosity, have you done a re-jet ? Those main/pilot jet sizes are what my manual has listed as stock. I think that the pilot jet, in conjunction with idle screw, would cause nearly everything you have described. Try going up one size on both to a 45 pilot and 175 main. Seems that for sportsters, the screw needs to be about 2.5 turns out for almost any stage 1, maybe slightly less or more depending on your particular engine. Not sure of the your needle, but most people I know don't bother changing their needle as the sportster needle is pretty darn good at what it does, particularly for 1200 models.

hope this helps

john

Hard to give accurate info with out seeing the bike with jetting but I would suggest take a reading from the fuel air screw if the bike running better with the fuel air screw in carbi at 2.5 turns out or more then definitely increase pilot jet up 1 or 2 sizes if you get the bike to run well between one - two turns out on the fuel air screw that is where your jetting should be
I wouldn't be concerned with main jet at all - it should be fine for wide open throttle unless you feeling power loss when you open it right up
also if you are getting backfire or popping when de accelleration that also hints toward lean pilot so a size or two change in pilot jet would be worth trying

There are probably 15 different main jets, 15 different needle jets, and 15 different pilot jets available for your bike. Go to www.babbittsonline.com/parts/viewbybrand/parts.aspx Input info on your bike then go to "carburetors" in the drop down list. Please rate my answer.

You are dealing with Suzuki vacuum carbs, you cannot just replace the air box and re-jet. What you are running into is there is no pressure to raise the diaphragm because there is no restriction to create such vacuum. Either put the stock box back on or go to the biggest main jets you can buy. Sometime even when you get stage 3 jets you still have issues. Vacuum carbs are not made to run with no restrictions.....putting aftermarket exhaust on it will make things much worse.

experiment with a few differant jet sizes cause there cheap and you'll figure your jetting out faster, so with the pilot i would grab a size 38, 40 and 42 and maybe a 44. the main jet id go with a 172- 175

should run then we had a fzr 600r and did work to it so i know from experience..