Mikuni Tubing

[dreamweavr124]

After searching a bunch and not finding a definitive answer, i guess i will just swallow my pride and ask.
Ever since rebuilding my carbs myself, they have not been working right. Long story short, i have now done everything that i think relates to my problem and had a professional redo my carbs. Now, when i installed them, something came back to me that the mechanic said; "there was surprisingly little fuel in two of the carbs". Since a vacuum/pressure problem was always one of the questions, i want to make sure that i hook up all the tubing correct.
My carbs for the 78 GS1000 have the main fuel line intake with the filter on it connecting to the "T" located in the center. What i am confused with all of a sudden is that carb #2,3,4 all have valves pointing up towards the gas tank. What one do I connect the petcock to? What about the others?
Thanks so much for the help. Sorry if this is a redundant question.
Steve

[7981GS]

The one closest to the engine is your vacuum port that goes to the petcock.
The other two are vents that should run either over your air box and down or just up through the frame cross tube in front of the battery and down where your battery drain hose goes.
Usually, there is a small caged area for all of the hoses to go through towards the back rear of the engine.

Eric

[cowboyup3371]

Looks like Basscliff hasn't given you your official welcome as you haven't actually introduced yourself to the site. Try going to http://members.dslextreme.com/users/...locations.html to get your immediate answer to start off with. Also, get your service manual from his main site (http://members.dslextreme.com/users/bikecliff) and read up on lots of other good info.

Might do you good to post up something about yourself in the GS Owners section as well as include pics of the bike. Be sure to also put your location in your profile and your bike info in your sig so you won't have to remember telling us and we won't ask as much.

Finally, make sure everything has been done per the top ten newbie mistakes as well as the top ten maintenance needs found on Cliff's site.

[OldVet66]

The nipple on carburetor #3 (left to right) is petcock vacuum and the nipple on #2 and #4 are vents on the VM carbs. The nipples are on the left side of the carbes. If 7981 GS meant the one closest to the center of the engine, that would be correct, but they are all in exactly the same position on their respective carburetors 2, 3 and 4. There is not one on #1 where your choke lever is. Check that your air adjust screws face outboard, 1, 2, left, 3, 4 right. The way they are cast I guess you could switch 1 and 4 and end up with them getting no fuel.