funky carb issue!

[Venturerscott]

ok, i got the carbs clean, changed the plugs. she idles without the choke... on 2 cylinders! checked the spark on the front bank, and have spark. spray anything flammable in the front carbs, and the idle picks up and smoothes out pipes start getting warm. then it burns off the fluid and it goes back to sounding like a sick harley. cover the carbs and it pulls fuel into the throat. anyone got a suggestion? i wanna ride when mother nature gets back on her meds! im guessing something in pilot circuit... but on 2 carbs acting the same... on the same bank... also it will not rev past a certain point approx 1800-2200. it will start to rev, then bog, and finally stall. my xs would at least rev up to the point that the mains would feed it. are these carbs that finicky?

[CaseyJ955]

ok, i got the carbs clean, changed the plugs. she idles without the choke... on 2 cylinders! checked the spark on the front bank, and have spark. spray anything flammable in the front carbs, and the idle picks up and smoothes out pipes start getting warm. then it burns off the fluid and it goes back to sounding like a sick harley. cover the carbs and it pulls fuel into the throat. anyone got a suggestion? i wanna ride when mother nature gets back on her meds! im guessing something in pilot circuit... but on 2 carbs acting the same... on the same bank... also it will not rev past a certain point approx 1800-2200. it will start to rev, then bog, and finally stall. my xs would at least rev up to the point that the mains would feed it. are these carbs that finicky?

 

Yes, they are that finicky.

 

WHen you said you got them clean what did that mean? Did you have them off? I would try a "shotgun" with some compressed air and see how that goes since it's fast and easy and usually effective at clearing things out.

[Venturerscott]

i had them off. had them apart, cleaned them with carb cleaner through all the passages and compressed air. even being finicky wouldnt it at least rev to the mains? it just falls right on its face... my xs would rev up if you played with it, this one wants nothing to do with that. well after it stops raining i will attempt to do a shotgun cleaning.

[Dj Danger]

Same issue I noticed on mine today, rear 2 cylinders not hitting, fire on both plugs. Pull the choke out, and the back 2 cylinders kick in. I'm taking her into the mechanic Friday, to have all 4 of the carbs rebuilt, synced, and tuned.

[Marcarl]

Some things I might suggest to check out.

- have you got the right airfilter and in place.

- are the diaphragms seated properly, no holes.

- are the slides moving as they should

- are the enrichment valves returning to closed, or are 2 of them stuck (choke)

- are the floats at the proper levels.

[BlueSky]

Even though you said it had spark, the spark could be weak. Have you cleaned the wiring connections? How old are the spark plug wires? I clipped a half inch off mine and it seemed to make a difference. The copper core at the cap ends was corroded.

[Flyinfool]

Also how old are the spark plugs. These bikes do like clean NGK plugs.

[cimmer]

Kinda sounds like the pilot screws are not properly adjust on carbs 2 and 4, the front pair. This could also be a clogged passageway for the fuel to get to them. I would recommend turning them all the way in, clockwise, gently till they are seated and turning them out 2 1/2 turns and trying starting it them. This might solve the issue if that is all that is wrong. You will also want to sync the carbs once you getting it running.

Good luck and let us know what you find.

Rick F.

[Venturerscott]

new wires... lit me up. new plugs... brand new ngk iridium.

[coreyhill]

Check you joints and ducts. They will sometimes crack and let to much air in causing a air/fuel mixer problem. Hope this helps.