bike died temporarily

[Guest]

While riding back from home town to work town last night(55 mile trip), I was cruising along at 70-80 just fine. At 10 mile to my destination, I could feel it stating to stutter and miss a little bit. I reduced speed and switched to prime without much change. Then it started to feel like a cylinder was shutting down. I pulled the chock and it briefly got better then went back to sputtering finally all power lost I pulled onto the median. I popped the cap and attempted to start it fired a little but no luck. Atafter pulling the seat to jiggle wires I tried to start again and it fired-up with no issues the remaining miles but I kept the speed down. Ive had this happen before and it turned out to be a pulled wire from the battery to ignition. Im going to check that wire but I guessing some debris in the tank so Ill pull the petcock and check for stuff in there too. Ill post results so maybe this will help someone else ibn the future.

[sedelen]

I have an '82 GS1100E and recently it has been doing things similar as to what you described. Cruising around 75 and riding while in "Prime" it started ever so slowy to start slowing down, so slowly like I was almost imagining it. I gave it a little more throttle and it started accelerating again, then it started slowing down again. So I gave it more throttle and nothing, as it continued to slow down. I pulled over and switched the petcock from "Prime" to "On" and it almost immediately got it's power back. It did this somewhat the time out before but it never really slowed down, just seemed to be hesitating, not running smootly, it was in "Prime". I took it out yesterday to see if I could duplicate that problem, there were no problems, but I was running at less than the 75mph it did it before, so I found a highway where I could get and maintain that speed for awhile, I could feel it hesitating, but it didn't slow down. When I switched the petcock from "Prime" to "On" the hesitation stopped.
So, I've been thinking, the petcock filter affects all 3 positions, so I doubt that would be it. But then again, I probably should'nt be running in Prime to begin with.
I'm thinking now that the fuel might be metered out in less volume in Prime than On and Reserve. Or there might be a build up in the petcock for the Prime function. I don't really know if it's a problem or not, as the only thing the owner manual says about Prime is to use it when it hadn't been run for awhile. Doesn't say anything about running it in "Prime".

I was thinking about draining out a specific volume of gas in Prime and see how long it takes, then do the same thing in ON and see if it takes less time to get the same amount.

[JEEPRUSTY]

Prime has a smaller orifice.
That being said I can run my bike WFO in prime and suffer no starvation.

I would guess you have a fuel line problem. A petcock vacuum problem or the petcock itself needs replacement.

[sedelen]

Prime has a smaller orifice.
That being said I can run my bike WFO in prime and suffer no starvation.

I would guess you have a fuel line problem. A petcock vacuum problem or the petcock itself needs replacement.

My bike falters in "Prime" and since as you stated "Prime" has the smaller orifice that in itself could be the problem. I have no hesitation, slowing down issues while the petcock is in the "On" position perhaps because as you say it has a larger orifice.

[snicrep5]

i checked all the things I mentioned and everything looked good. but i found the #2 intake sleeve had gotten sucked in a bit causing a worsening lean condition.This might have also affected the vacuum on the petcock too. I changed the jetting recently for new exhaust and got careless on reassembly i guess.

[Maddevill]

Prime

I'm not sure but doesn't the Prime position take fuel from the very bottom of the tank? Could be some gunk or water getting to the carbs.

[Big T]

i checked all the things I mentioned and everything looked good. but i found the #2 intake sleeve had gotten sucked in a bit causing a worsening lean condition.This might have also affected the vacuum on the petcock too. I changed the jetting recently for new exhaust and got careless on reassembly i guess.

That sounds like it could be the problem

Did you break the intake boot?

[mrbill5491]

i checked all the things I mentioned and everything looked good. but i found the #2 intake sleeve had gotten sucked in a bit causing a worsening lean condition.This might have also affected the vacuum on the petcock too. I changed the jetting recently for new exhaust and got careless on reassembly i guess.

That is kind of what happened to my bike. I would be jetting right along and it would start acting like it wasn't getting any fuel and just die. I would stop and pull the vacuum hose off the #2 carb and suck on it and hear the valve open in the petcock. I would stick it back on and it would be fine pretty much the rest of the day for some reason. I then got some carb spray, fired the bike up and shot some of the spray around the boots of #2 and found it had a slight crack in it. Good thing was, the crack was where I could reach it so I put some silicone sealer over it and it sealed up until I could buy some new boots. What happened was the boot would warm up and expand the crack just enough for it to loose vacuum long enough for the petcock to close.

[sedelen]

I'm not sure but doesn't the Prime position take fuel from the very bottom of the tank? Could be some gunk or water getting to the carbs.

Very well could be, which is why I do run it in Prime sometimes, to clear out all that water, if any which settles to the bottom. Even still, I would think that it would clear it out within a short period of time. I do use fuel stabilizers to help keep the fuel freshened up. But I did just swap over from using Star Brite "Star Tron" to Marine Sta-Bil, perhaps that has something to do with it. I can't remember it doing that when I was using Star Tron.
I run my GS1000 around on Prime all the time, never had a problem.
Sorry for hijacking this thread, but I thought my problem was similar enough to where it might be the same thing.

[niels nielsen]

fuel starvation: I have it too

I have a 1980 GS1000GL with the vacuum-actuated petcock. Years ago, the previous owner had the bike fail while under way and the repair tag from the shop said the petcock was malfunctioning and they "repaired" it. But what they really did was reassemble it backwards, so it would NEVER CLOSE . When I bought the bike and disassembled the petcock to clean it out, I discovered this and reassembled it correctly- and now, if the bike has been sitting for more than four days, the petcock will stick shut and I'll run the battery flat cranking the engine to get it to start. BTW the "prime" position on mine apparently does not pass fuel either, so I cannot simply drive around with the petcock in the prime position all the time and call it done. What I REALLY want to do is replace the petcock with a manual one.

(As an aside, the first time I went through the petcock I missed removing a teeny piece of rotten O-ring from inside it, which restricted the fuel flow just enough to starve the engine after driving the bike one mile. Before I figured that out, I had to push the bike a full mile home TWICE. Now THAT was a lot of work! And very educational...)

This extremely frustrating fuel problem is the only flaw in an otherwise very well-designed and well-built machine, which is the nicest and most well-mannered "big bike" I have ever owned. Switching out the petcock is on the top of my to-do list for after the holidays.

Best regards,

Niels Nielsen in Corvallis, Orfegon