#3 carb not idling.

[aujax]

Hi,

Just having some trouble with my #3 carb idling. It doesn't want to idle no matter what i do - the position of the fuel screw underneath doesn't affect it. I've cleaned the carb thoroughly and the pilot jet and pilot holes are clean and carb cleaner sprays through them when the carb is disassembled. Any ideas?

Thanks,
Aujax

[Dave8338]

At the risk of sounding like a broken record...have you tried a new plug?

[Steve]

Ideas? Yes. First, let us know what bike we are discussing.

Second, when you say "I've cleaned the carb thoroughly", what do you mean by "thoroughly"? Did you dip them overnight in Berryman's? A quick spray or even a poke with a wire is not going to clean them as good as they need to be.

Soak all your metallic parts (for one carb at a time) overnight to make sure they are clean, then you can spray with carb cleaner and compressed to be really sure, then you can re-assemble.

.

[aujax]

carb cleaning

yeah, i've changed the plug, cleaned the carbs - soaked overnight, had them professionally cleaned, inspected them over and over. the spark i'm getting is good and i cant find any plugged up holes...

[aujax]

idling

sorry, it's a '79 gs750.

[spyug]

Just having some trouble with my #3 carb idling. It doesn't want to idle no matter what i do

I'm not sure what you mean. Do you mean the engine will not return to idle when revved? How do you know specifically that carb #3 is at fault.

Could you be a little more specific as I'd like to help.

Cheers,
Spyug.

[aujax]

idle

Well, i know it's not idling because the #3 exhaust doesn't get hot when i start up the bike and let it idle. it does get hot, however, when i give it gas and i can tell that i'm getting full power from the bike - all four cylinders are firing.

[catbed]

sync your carbs.

[greg78gs750]

let me know when you get this figured out, my 78 750 does the same thing.....which is very frustrating to me. i'll be following this....

greg

[RJz1100E]

Mine was doing the exact same thing. Then the Chefinator cleaned, re-o-ringed, rejetted, adjusted float levels, and bench synced my carbs. The problem is gone. Dig deeper man!

[tanner8308]

#3 Carb no fire

I have had the same problem with my 1977 GS750B. What is it about the #3 carb, the vacume tube to the pet cock is the only unique thing I can think of? Does any one have a diagram of the mikuni vms that are on the early GSs? What does the screw under the carb body in front of the float bowls on the engine side control?

[SAN]

#3 cyl no idle

Check out www.gs-classic.de/index1e.htm for some images of idle circut diagram.SAN. good luck, they also have info models yearby year you have to convert german to english follw instructions.

[aujax]

screw

tanner, the screw underneath adjusts the idle for each carb - it controls how much fuel flows through the idle hole in the carb. This is a tiny pinhole near where the mouth of the carb is (on the end that meets with the engine).