'79 GS1000E Petcock Vacuum Line Location

[sedelen]

I'm a little perplexed, and I can't locate the info in a service manual. I always thought the petcock vacuum line went to the No. 2 or 3 carb ('79 GS1000E).
I had my tank off today and did not see any location for the vacuum line on the carbs.
I knew I had an air leak in No 2 carb manifold and suspected the O rings in the carb manifold.
I found the source of my vacuum leak, on the No. 2 cylinder sync port, instead of a allen screw with washer, I have a threaded nipple that isn't
connected to anything, just sucking air. This is where I believe my petcock vacuum line was connected to. Not long ago that line disconnected, and I reconnected it to another vacuum line that went to carb No.2, and I believe that line went to the top of the carburetor, as with all the other carbs, but it was sucking air, so I assumed that was "the" vacuum line for my petcock and I took a barbed nipple and connected that line to my petcock vacuum line.

So, here's my question, Is the threaded nipple coming out of No. 2 sync port the place where I hook up my petcock vacuum line? (I checked the parts fische and it lists 4 sync port screws per engine and it doesn't show or list a threaded nipple)
The bike runs better since I disconnected it from whatever hose that was (which was sucking air) and reconnected it to that No. 2 carb manifold sync port.
Any clarification you can give me will be greatly appreciated.
Thanks in Advance.

[tkent02]

Give us a picture of your carbs, It sounds like someone swapped them out for carbs with no vacuum nipple, which should be on number three. So they had to use the vacuum synch port on the boot instead. You may have some really expensive performance carbs there.

[azr]

Sounds like someone has done some 'special' mods to the bike. Go find some allen head screws with washers and get those nipples out of there. I assume someone was trying to make an easier set up for synching the carbs...unless they accidentally left the threaded nipples in there from doing a carb synch (you use just such a nipple when doing carb synchs). If that is the case keep all four of those, you might have a use for them. Your vacuum line from your petcock will attach to a vacuum port on carb number three, not carb number two, but it's easy to tell which carb is the right one as only one will create vacuum from its port. My 78 1000 is that way, my 79 850 is that way and I'm pretty sure yours is the same. Sounds like you already fixed it. Check out Basscliffs site for some manuals and carb walk throughs. Best of luck with the repairs.....any pics??

[sedelen]

Give us a picture of your carbs, It sounds like someone swapped them out for carbs with no vacuum nipple, which should be on number three. So they had to use the vacuum synch port on the boot instead. You may have some really expensive performance carbs there.

I haven't quite figured out how to post pictures yet (which is why you've never seen any from me, LOL), the carbs look just like the ones in the fische, I believe they're original, just like the ones I had on my '78 Skunk but with the choke knob on the ignition instead of the carbs by the petcock.

[sedelen]

Sounds like someone has done some 'special' mods to the bike. Go find some allen head screws with washers and get those nipples out of there. I assume someone was trying to make an easier set up for synching the carbs...unless they accidentally left the threaded nipples in there from doing a carb synch (you use just such a nipple when doing carb synchs). If that is the case keep all four of those, you might have a use for them. Your vacuum line from your petcock will attach to a vacuum port on carb number three, not carb number two, but it's easy to tell which carb is the right one as only one will create vacuum from its port. My 78 1000 is that way, my 79 850 is that way and I'm pretty sure yours is the same. Sounds like you already fixed it. Check out Basscliffs site for some manuals and carb walk throughs. Best of luck with the repairs.....any pics??

I only have one nipple on a carb sync port, which is located at No. 2,
1,3 & 4 all have allens with washers. I believe all four sync ports should have allens with washers (am I wrong here?) I believe this nipple like you
suggested is leftover from a sync tool, and either someone couldn't remove it or decided to use that as the vacuum for the petcock. I believe the vacuum line which I connected my petcock vacuum line to (the petcock vacuum line fell off from wherever it was connected, and shut the gas off to the engine, had to make it home on "Prime") was to the No 3 carb, it was and still is sucking air. I used a barb nipple to connect the two lines which were different diameters. That allowed gas to get to the carbs, but left that sync port nipple sucking air. Still the bike ran pretty good, I only stumbled on it by accident.
If I can get two nuts to thread on that nipple and tighten them together, I might be able to back out that nipple. Then I could connect the petcock vacuum line to that No. 3 line which is sucking air. Or I could leave as is and pinch off or plug that vacuum line which I believe goes to No. 3 carb.
Before I would do that I would check those other lines to see if any of those are sucking air.
The bike is up and running, and it runs pretty strong, I only pulled the tank off to get it repainted and replaced it with a spare when I found this.

[sedelen]

Update!
That vacuum line that's sucking air does indeed go to No. 3 carb. Two and four do not suck air, and one doesn't have one. So, I plugged up that line and had to adjust the idle as my RPM dropped dramatically. I reinspected that nipple at sync port No. 2 and there's a gray substance coating a large part of the threads, I'm not sure but it looks to be some kind of expoxy, JB weld or something. I may not be able to get two nuts on them
for an extraction and replacement of the Allen screw and washer. I suspect seeing some of the other work that was done to that bike by prior owners, that someone tried to glue on the vacuum line.
Does anyone know off hand what size screw that is?

[azr]

You need to do a simple hose clean up. Connect your petcock to #3 carb and plug that weird thing on #2 synch port or better yet get rid of it. Not sure of the screw size but just take out one of the others. Its a pretty generic size. Your bike should run a lot better with this sorted out. If you go to Basscliffs web site he has great tutorials on where all the hoses go and how to post pictures. Spend some time on his site, there is tons of stuff in all kinds of nocks and crannys.

[sedelen]

You need to do a simple hose clean up. Connect your petcock to #3 carb and plug that weird thing on #2 synch port or better yet get rid of it. Not sure of the screw size but just take out one of the others. Its a pretty generic size. Your bike should run a lot better with this sorted out. If you go to Basscliffs web site he has great tutorials on where all the hoses go and how to post pictures. Spend some time on his site, there is tons of stuff in all kinds of nocks and crannys.

That's pretty much what I planned to do was to return it to original. I'm sure the petcock vacuum line was connected to No 2 sync port nipple when I bought it. The hose is hardened past where it fits on that nipple and I think that's from the engine heat. That line fell off shutting my fuel off, I found No. 3 carb vacuum line sucking air and connected it to that with a barbed nipple, not realizing it was now sucking air through the nipple at the No. 2 sync port. I really don't want to crush that nipple getting it out of there. Two nuts tightened together then just unscrew it, but I think I got epoxy on the threads. I'm going to take a wire brush to it and see if I can clean off the threads, if I can't get it that way I can stick the largest allen wrench into the hole that will fit so as to not crush the nipple when I try to back it out with a pair of needle nose pliers. I may just cap off that nipple with a piece of hose burned closed on one end and reconnect the vacuum line from the petcock to the No. 3 vacuum line with a barbed nipple like I had it until I replace my spared tank with the repainted one in December. I'll be replacing some parts then and will replace that short No. 3 carb vacuum line with a new one. I'll updat on my progress.
Thanks for your help.
This is a great site! No doubt about it.
And one day, when I'm not too busy wrenching I'll take the time to go back through BassCliff's site and give a shot at posting pic's.

[Steve]

I reinspected that nipple at sync port No. 2 and there's a gray substance coating a large part of the threads, I'm not sure but it looks to be some kind of expoxy, JB weld or something.

It sound like that gray stuff IS JB Weld. If so, I would leave it and get a cap for the nipple. As long as you have a tight-fitting cap on there, it will not be a problem. I have a feeling that the JB is there because the threads are stripped, so if you manage to extract that nipple, you may find that you now need to replace the boot. You know how it goes, ... "since I'm replacing one, I might as well replace them all"

.

[sedelen]

It sound like that gray stuff IS JB Weld. If so, I would leave it and get a cap for the nipple. As long as you have a tight-fitting cap on there, it will not be a problem. I have a feeling that the JB is there because the threads are stripped, so if you manage to extract that nipple, you may find that you now need to replace the boot. You know how it goes, ... "since I'm replacing one, I might as well replace them all"

.

The gray stuff, probably JB weld is on the lower portion of the threads, the theads going into the engine seem to be free of it. This nipple has no nut on it, it might take an allen, but the sync port on this bike in not on the manifold but on the head near the manifold. I'm going out and see if I can extract it without too much effort. If it is stubborn I will leave it alone until I come up with a better idea.
Thanks

[sedelen]

It took some effort, but I got that stubborn nipple out. It had what appeared to be JB weld on the lower threads and lock-tite on the thread
that screwed into the sync port. A easy out did the trick, now the bike's
vacuum lines are reconfigured back to original and the bike runs great.

Thanks to all the worked with me on this!