82 GS1100 eventually dies at idle

[Guest]

Bike was re jetted for K and N pods before I bought it with a Stage 3 Dynojet kit. Had been sitting for 2 years before I bought it so it really wouldnt idle. After a carb clean and getting the gunk out of all the jets it ran (and runs) great. Replaced some other worn out rubber parts like the boots for the carbs/intake ports. One of the carbs leaked after the clean, until I replaced an o ring for that needle jet (after much research on here!).

*************Bike has been running great and is scary fast but if you're at a stop light, in about 5 seconds the idle will eventually slow down and I'll have to open the throttle a millimeter or two to compensate and hold it like that to keep it revving high enough to stay running. If i dont hold it like that the bike will eventually konk out ever so slowly. *************

Adjusting the speed of the idle (with that 1 main screw under the set of carbs) doesnt work either, the idle will just hang when i blip the throttle, and if i just let it idle with my hand off the throttle, it will slowly die unless i keep turning that needle in.

The fuel screws on top of each carb are about 2 turns in (It says 2 1/2 in the manual but the main jets are bigger than stock). I've tried a little more in, a little more out (on each) but I don't notice a difference.And yes. I have wanted to do a proper carb synch but the little screws to hook up the synchronizer tips to the intakes are f$#kin rusted shut like a mofo. I have already stripped other screws on this bike (and luckily got them out with an extractor or pulverizing said screw with a masonry drill bit) and I just know thats what I'm in for if i try to torque them open. I've let liquid wrench marinade on those babys over night and all that good stuff and still nothing. Damn previous owner let it sit outside so they are really weathered on there.

Any ideas good people of the forum? I have no other issues other than this idle issue. I mean i can still ride it around but its basically annoying to have to hold the throttle in a tad if im at a light.

Any advice is greatly appreciated.

[mmattockx]

The fuel screws on top of each carb are about 2 turns in (It says 2 1/2 in the manual but the main jets are bigger than stock). I've tried a little more in, a little more out (on each) but I don't notice a difference.

Assuming you mean the pilot screws are 2 turns out, not in, I would say the screws should be ~3-3.25 turns out to run pods, using the stock pilot jets. You will be quite lean at idle with the screws 2 turns out on the stock pilot jets. My 82 1100E is at 3.25 turns out with APE pods and a Kerker 4-1 exhaust. I don't imagine it would idle at all with the screws set to 2 turns out and it is a Canadian model which came with a larger pilot jet than the US model came with.

I am no help on the frozen vacuum port screws, sorry.


Mark

[thewarthog]

Assuming you mean the pilot screws are 2 turns out, not in, I would say the screws should be ~3-3.25 turns out to run pods, using the stock pilot jets. You will be quite lean at idle with the screws 2 turns out on the stock pilot jets. My 82 1100E is at 3.25 turns out with APE pods and a Kerker 4-1 exhaust. I don't imagine it would idle at all with the screws set to 2 turns out and it is a Canadian model which came with a larger pilot jet than the US model came with.

I am no help on the frozen vacuum port screws, sorry.


Mark

Hmm. I've had all of them at 3.25 turns out in the past when trying to figure it out but it seemed to run even worse when accelerating like something was holding it back. I suppose its worth another shot though, they're pretty easy to get to.

[gustovh]

Check the vent on the gas cap, comes apart with just a couple screws. Couldn't hurt.

V

[posplayr]

have you checked the voltage?


Quick Test

[Big T]

Tight valves will cause fading idle

[cowboyup3371]

So will a vacuum leak around the carb to engine boots or the O-rings behind them

[thewarthog]

Thank you all for the input, it is much appreciated really. When I get back from work today I will take a look at the items you all mentioned and try to single out the culprit and post the results.

[roeme]

And if it's not an air leak, then it's loose screws. Recently had moving/hanging idle on my 550; bolts shaken loose allowed two carbs to move every so slightly, which in turn moved the needle position, and made for a very elusive troubleshooting.

[thewarthog]

Started with the easiest and most obvious thing mentioned, the gas cap, and that appears to be the damn culprit. Wish I had taken a before of this picture I’m including, all that shiny metal was all sooted over black, there was a port behind it that I think was getting blocked as now it idles like a sewing machine and I can visibly see more fuel going through the clear in-line filter I have. About to take it for a test ride. I hope it really was that easy!037B7DCD-C6C2-4556-B931-F100D11A0319.jpg

[thewarthog]

D6CF1055-55E2-4905-BC3D-8EB6E92FD42F.jpg another pic for reference

[thewarthog]

Never mind, wasn’t the vent cap, that was too easy

[thewarthog]

The first reply on this thread was right,it was the fuel mixture screws above the carbs, moved them closer to 2.5 2.75 turns out and walla.

in the words of the fictional Kenny Powers, “finally motherf-/cker”

[roeme]

(...)moved them closer to 2.5 2.75 turns out and walla.

(....)

European nitpick: Its voilà, or in a pinch, voila.

Let's hope that was indeed the culprit.

[thewarthog]

Update: So it still seems to come and go now, sometimes I wont need to pull the throttle back a tad and sometimes I'll still need to to keep it pulled back a millimeter or so. I checked the voltage and the battery will be in the 14.2-14.4v range when I rev it up like the manual says, so I think i can the charging system out?

Im leaning towards a vacuum leak just cause of how she has been acting so I am going to put a little more grease on the o rings for the carb intake boots. I replaced them with OEM rubber boots and rings and just put a little bit of lubricant on the o rings during the install, but I remember wishing i had something with a little thicker consistency, more like a grease than a lubricant I suppose.

Another poster said the engine vibration possibly due to loose screws in this area could be causing this? I do have pods rather than an airbox so theres no bracket holding all that in place like the airbox typically would, so I guess that could be the issue. I'll make sure everything is nice and snug on re-assembly.

Update to follow.