Repair Issue: Dealer and I Baffled

[Anonymous]

Here's the history of this problem regarding my '83 GS 1100L. I was getting ready to ride the bike out of state, and noticed the smell of gasoline in the crank oil. I rebuilt the petcock and changed the oil twice, then rode the bike ~70 miles without incident. I rode the bike to and from work the next workday without incident. The second workday, I rode the bike to work no problem, but when I was ready to go home, here's what happened: bike started right up on full choke, fast idle no problem. As I backed off the choke as I normally would, the bike would not take throttle, and sounded like it was not running on all 4 cylinders. I got about 2 blocks down the road, the bike wouldn't take throttle no matter what the choke position, and died. It acted like it was out of gas. I tried the prime position on the petcock, but the bike would not restart. I tried every choke position, throttle position combo I could think of, but no starting. I pulled the plugs, on 3 & 4 and they were bone dry.
I had the dealer, which has been around for decades and is quite familiar with these old carbeurated bikes pick the bike up. They thought my idle circuits were clogged. They pulled the carbs, cleaned them & reinstalled them. Petcock checked out o.k. and floats were o.k. Vacuum line o.k. Ignition o.k.
When I picked up the bike, it wanted to run on 3 cylinders despite running fine in their tests the previous day. Some out-of-gear revving brought back the other cylinder, and I rode the bike home without incident.
I then rode the bike to and from work without incident. The second workday I tried to ride it to work, and it did the same dying trick. I pushed it the several blocks home, called the dealer to come pick it up. Both of us are scratching our heads. It's intermittant; gotta love intermittant problems.
What do you think is happening here?
Scott

[nabrams]

I had a similar problem. In very hot weather the float in my left carb would get hung up and prevent the float needle valve from opening (when I removed the bowl there was no fuel in it). It turned out that when the bike got hot the bowl gasket and float would expand just enough to touch.

[Anonymous]

Repair Issue: Dealer and I Baffled

Thanks, nabrams. I'll pass this info along to the mechanic and see what happens.
Anyone else have any ideas out there?
Scott

[80gs1000e]

Clogged fuel lines?

[Anonymous]

vent

vent system?tank -carbs

[redliner1973]

partially clogged tank..

[Planecrazy]

Gremlins?? 8O

I like the float bowl idea myself ... check for too much play at the pivot points of any fuel related moving parts ... could cause rubbing and sticking -- just a wild guess...

Good Luck,
Steve 8)

[Anonymous]

I think you have a not-so-well tuned bike in the first place, and two or more other problems causing this freakishness.

If I was troubleshooting this problem I would try to isolate the problem by checking the system at several points. Check fuel flow from the tank, which might get dangerous on a hot bike. Pull the plugs. Check residual color and spark.

When it runs on three cylinders, try to feel which ones are running and which are not, by feeling the radiated heat from the exhaust pipes. It's good to know which one has the problem.

Clogged vents or gas cap other wackiness has been known to cause spurious fuel starvation. When it happens again, you might want to pull the gas cap off, relieving any vacuum, give it ten seconds, and try to start it again.

If your dealer's mechanic can't track this down, you need a better mechanic. Simple fact.

[Bill + Karen]

Is there a inline fuel filter? If not it needs one, paper preferably. Any way thats my guess, crap coming from the tank. Had/ have simular issues with the 550. Bill , ........... Just had another light bulb light up (dimm at best) Same said crap will also cause petcock sealing issues. :?