carburator coughing

[deepseamax]

Hello,
I've done the "shot gun", synchronized the carbs, and currently running sea foam in the fuel. At low gear and rpm, I'm still getting a "cough". I took the air box out and watched what was happening. If you look straight down, and turn the throttle a little, the needle and associated rubber boot (terminology is probably wrong) pop out towards the front of the carburator (a plum of exhaust like vapor occurs along with the pop). At higher rpm and gear, it seems to run fine. What to do?

 

[SpecOps13]

Where are your Air / Fuel Screws set???? How many turns out???

 

[deepseamax]

f/a mixture screw set 2.5 turns out.

 

[SpecOps13]

Try turning them out another 1/2, that will make them slightly richer. If that helps, you have an answer. If not, drain the front left carb into a clean paper cup or glass jar and see if there's any trash in what comes out... The Shotgun May have loosened things up and they moved into the carbs low speed jets...

 

[bobzdar]

I had this happen to me when two of the rubber boots that go from the airbox to the carbs got hard and wouldn't seal properly. I replaced them and it seems to have fixed the problem as I now get a good seal.

 

[tugla]

also check sync, when was the last time you did that?

 

[KJShover]

To me it sounds a little lean in that carb.
+1 on backing that carbs a/f screw out another 1/2

 

[Fastatv]

Hello,
I've done the "shot gun", synchronized the carbs, and currently running sea foam in the fuel. At low gear and rpm, I'm still getting a "cough". I took the air box out and watched what was happening. If you look straight down, and turn the throttle a little, the needle and associated rubber boot (terminology is probably wrong) pop out towards the front of the carburator (a plum of exhaust like vapor occurs along with the pop). At higher rpm and gear, it seems to run fine. What to do?

Had what sounds like a similar problem with mine. I took someones advise here, don't remember who it was. Anyway, warmed up the engine, took the air/fuel screws in, one at a time till cylinder died, then turned out the screw until I had a smooth idle, then out another 1/2 turn. I did this on each cylinder and for my bike, this made the greatest "off idle " improvement of anything I tried. Mine still coughs but it's a very rare occaision and before, it coughed "off idle" about every time I rode it.....was really pissing me off :damn angry:. There is a sticky on this in the carb section. Good luck! Rick

 

[deepseamax]

Thanks for the advice. Will try all, and see what happens.

 

[SpecOps13]

Good Luck deepseamax.....