77 GS750 Carb Issue? Someone please give me a call!

[krsmetalhed1988]

Got a 77 that I am trying to get on the road before bike week in Daytona starts. Bike is no longer stock with the carbs being rebuilt about a year ago. Engine has not been run yet. Something weird is going on with the #3 carb. Cranked the bike over with no gas and air was blowing out of the #3 carb nipple that is next to the inlet, guess these ports were connected to the stock airbox? I then put gas in the carbs and during cranking the bike gas shot out of that same spot. I pulled the carbs and adjusted the float levels because they were not correct. With the bowls off I blew air in the other two nipples and the air blew into the bowls and not into the carb intake/head like #3. Carbs are my arch nemesis, someone please help and give me a call! Chris 912 270 1780. I am a past member but my account got deleted because of inactivity.

[TheCafeKid]

Can you take a picture of which "nipples" you're speaking about? On the VM carbs, the #3 carb was the "master" and was where the vacuum line for the petcock connected if I remember right. Been a minute since I've had to set them up.
You say it's not stock, what have you done to it?
None of the "nipples" connected to the airbox. The bottoms of the float bowls had tubes for overflow that would have been routed down out of the back of the swingarm pivot area. And the vent lines would have had tube that routed up over the airbox. But if you're running pods, the vent hoses should be removed.
If you're overflowing, are you sure:
A) your petcock hasn't failed
B) your float settings are correct
C) the carbs have new orings inside and the float needles aren't bad?

[chuck hahn]

Yes..3 is the nipple that the vaccuum to the petcock goes to. Put a piece of vacuum hose on it and the small nipple on the petcock. If you have an aftermarket petcock that doesnt have a vacuum port, then cap the nipple on the carbs off with a rubber cap.

[krsmetalhed1988]

when I say not stock I was mainly talking about the frame and such (bobber). Pod filters and bigger jets and custom exhaust. Engine is stock otherwise. I just adjusted the float levels. no petcock right now because the tank is at the bodyshop now. The #3 carb did overflow when I put gas to it before I adjusted the floats.

[chuck hahn]

So assuming the floats are correct, when you get the tank and petcock back, then put about half a tank of gas in it and set it in the ON position. Hook a length of fuel line to it and run it into a pop bottle and let it sit overnight. Check in the morning to see if theres any gas in the pop bottle..if not then good to go. If there is, then the petcock is most likely not sealing right. Better to check on the bench and discover a problem than fill the crankcase or cylinders with gas.

[TheCafeKid]

Have the carbs been rebuilt/cleaned? Did you inspect the float needles? If they've got a groove worn into them at the tip they usually need replaced as they won't seal well anymore....

[chuck hahn]

Josh..he says he has done them according to the service manual on Cliffs website..but didnt get the float hts right. He is just now buttoning them back up and will see if the overflow issue stops. Hes using a gravity tank to run the bike right now cuz the ntank and petcock are some where else. I advised him to be sure to clamp off the feeder line when the bike isnt running..

[chuck hahn]

Welllllll...progress report???

[krsmetalhed1988]

almost there, but having trouble with the bench sych. What order are you supposed to do this in? I did #3,#2,#1, then #4. Once I adjust #4 it changes the rest of the carbs.

[chuck hahn]

you have cv carbs then..thought you had the stocker VMs when we talked on the phone. 3 is the master cylinder. adjust the idle knob just till you get that slight gap like i said on 3..then adjust them to match. Look at the adjudter links from carb to carb and youll see what i mean and which ones are linked together.

[krsmetalhed1988]

Nope, they are the VM carbs.

[chuck hahn]

if they are VMs they are each independantly adjusted and not linked at the back like the Cvs..so I cant see why setting number 4 would change any of the others..doesnt make sense.