1982 GS1100GL issues

[TomsCycle]

I have this 82 gs1100l model that I am having some problems with. The bike starts and runs great. I am a full mechanic but can not figure this one out. I went through the carbs, cleaned, syncd, and reinstalled. The bike starts and runs great. It is as fast as it can be right now. If you are driving it around for a while 50-100 miles out of no where the bike will slowly start to bog down and loose all rpms. There is also no throttle response when this happens. You pull the bike over and let it sit for a bit and give her a little choke and it will fire up. Sometimes the bike will take right off like it never missed a beat, fast as hell again and able to pull a wheelies again but sometimes it will run like crap almost like it is starving for gas until I limp it home. I drilled out the baffles as well thinking that the exhaust might be clogging but no dice. I also changed the electrical system on it(everything that had to do with spark. Any help would be great. Thanks

[KINGB1949]

Have you checked gas tank and carb vents?

[Steve]

Did you drill out the baffles enough that you affected the backpressure and, therefore, the jetting requirements?

Reducing backpressure will lean out the system, making it run hotter. A hotter engine will start to seize lightly, making it run just like your description.

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[almarconi]

Did you drill out the baffles enough that you affected the backpressure and, therefore, the jetting requirements? Reducing backpressure will lean out the system, making it run hotter.

Steve, this is an interesting observation. I'm trying to rejet a KZ with a v/h pipe. I noticed that the engine heats up much quicker and runs much hotter than the GS. Even at 4 turns out with stock pilots, its still a bit lean. I'm going to try a larger pilot jet.

Would the pipe have an effect on all the jets?

I have not ridden it yet so can't tell is mains and secondary mains are where they need to be.

[Steve]

I don't have a whole lot of experience rejetting for pipes and/or pods, but I would suspect (guess) that a pipe would affect the entire range. Of course, at low throttle openings, even a very restricted muffler will flow enough to not matter much, but will really hamper higher flow rates. On the other hand, a freer-flowing pipe will not make as much difference at low flow, but flow a LOT better at wide-open settings.

Turning out the pilots to 4 turns is probably approaching their limit of adjustability. At that point, you might want to consider going up one size on the pilot jets, but only after making sure you have the correct main jet installed. If the KZs behave like the GSs, with just a pipe, you will want to go up 2 or 3 sizes on the mains and possibly raise the needles, too. If you have pods on there, too, you will want to go up 5 or 6 sizes on the mains and definitely raise the needles. If you want to make the process easier, consider getting a kit from DynoJet. If you have just the V&H pipe, a Stage 1 will do. If you also have pods, get the Stage 3 kit.

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[almarconi]

If you want to make the process easier, consider getting a kit from DynoJet. If you have just the V&H pipe, a Stage 1 will do. If you also have pods, get the Stage 3 kit.

If this were a GS or KZ which has mikuni carbs, I would get the dynojet. I've heard less than favorable results with the dynojet kits in the Keihin CV34 carbs.
I'm going to see the results I have with swapping jets and raising the needles.
Carb tuning is so much fun

[TheCafeKid]

If this were a GS or KZ which has mikuni carbs, I would get the dynojet. I've heard less than favorable results with the dynojet kits in the Keihin CV34 carbs.
I'm going to see the results I have with swapping jets and raising the needles.
Carb tuning is so much fun

When dealing with CV carbs, no matter the make, its best to work from the Main back. Because, in the CV set ups, the pilot actually draws thru the main. If the main is too small, the pilot will starve. Check out the tuning guide on Factory Pro's site, it was VERY helpfull to me.

[chef1366]

I have this 82 gs1100l model that I am having some problems with. The bike starts and runs great. I am a full mechanic but can not figure this one out. I went through the carbs, cleaned, syncd, and reinstalled. The bike starts and runs great. It is as fast as it can be right now. If you are driving it around for a while 50-100 miles out of no where the bike will slowly start to bog down and loose all rpms. There is also no throttle response when this happens. You pull the bike over and let it sit for a bit and give her a little choke and it will fire up. Sometimes the bike will take right off like it never missed a beat, fast as hell again and able to pull a wheelies again but sometimes it will run like crap almost like it is starving for gas until I limp it home. I drilled out the baffles as well thinking that the exhaust might be clogging but no dice. I also changed the electrical system on it(everything that had to do with spark. Any help would be great. Thanks

Check the petcock.

[mike_of_bbg]

I also changed the electrical system on it(everything that had to do with spark.

It's probably fuel, but I wouldn't assume anything. Did you install a Dyna system, new OEM components, or used but presumed good components? Carry around an extra plug and check spark the next time it happens.