Please! Help! Know repeating common problems is annoying but need advice.

[Guest]

First off, I’m new to the forum. Sorry to ask dumb questions and hope this is posted in the correct place. Sorry to bring up what other have probably asked over in over but Im stumped. I have a 80 gs1100L that I have been working on for the last couple years on and off after falling in love with a gs850L I picked up five years ago.

my gs1100 has been running like crap as of lately. have afterfire on the 3&4 tail pipe. A slight stutter at idle. Sluggish. Spitting and sputtering. And sometimes acts like its lean and other like its rich. Almost like an intermittent misfire. But checked spark. But heres the catch. While chasing this devil I have put in new plugs, wires, dyna coils, carbs completely rebuild (followed basscliffs notes) , has all new rubber boots intake and air box replaced. Petcock replaced. Checked for leaks. Dial synchronized. Tired adjusting the carb screws several times throughout this ordeal. Also tired one size bigger jet to accommodate the k&n filter with no success. Timing seems fine.. And it doesn’t seem like a valve problem. I did them last year they were making some noise. Each time I pull the plugs they look fine. I change my oil every 1000 miles and only run 91. A push in the right direction would be very appreciated.

[JTGS850GL]

Here's couple places to start:

1: Verify the voltage at the coils +12V lines AFTER the connector and before the coil.

2: Have you vacuum synced the carbs?

3: Have you checked your carb float levels and if so how?

4: Assuming you still have an airbox and the K/N filter is the standard insert. If not, then describe the filter arraignment.

5: How old is the fuel and have you drained your tank and performed a refill. Might be water condensation problem.

[Gunner]

Will check volts now. Has newer stator and new battery. k@n is in the stock box no cutouts or tampering. Dial vacuumed synced the carbs. And floats were checked with a caliper tool. Tanks has been drained, new fuel and inline filter as of yesterday.

[Gunner]

Has good Volts. Thank you for the input.

[posplayr]

First off, I’m new to the forum. Sorry to ask dumb questions and hope this is posted in the correct place. Sorry to bring up what other have probably asked over in over but Im stumped. I have a 80 gs1100L that I have been working on for the last couple years on and off after falling in love with a gs850L I picked up five years ago.

my gs1100 has been running like crap as of lately. have afterfire on the 3&4 tail pipe. A slight stutter at idle. Sluggish. Spitting and sputtering. And sometimes acts like its lean and other like its rich. Almost like an intermittent misfire. But checked spark. But heres the catch. While chasing this devil I have put in new plugs, wires, dyna coils, carbs completely rebuild (followed basscliffs notes) , has all new rubber boots intake and air box replaced. Petcock replaced. Checked for leaks. Dial synchronized. Tired adjusting the carb screws several times throughout this ordeal. Also tired one size bigger jet to accommodate the k&n filter with no success. Timing seems fine.. And it doesn’t seem like a valve problem. I did them last year they were making some noise. Each time I pull the plugs they look fine. I change my oil every 1000 miles and only run 91. A push in the right direction would be very appreciated.

Is this an GS1100E (16V)?

Most people (1100E) use the Dynojet 3133 kit. K&N pods alone will require more than one step. probably 2-3. EDITED i assumed you have pods not an airbox filter element. I had a GS750 16V and with an K&N element and lid it did well with an increase of one step.

https://www.dynojet.com/jet-kit-for-suzuki-gs1100/

[Gunner]

It’s a 1980 gs1100L, has the 16 valves. I went up from the stock 107.5, to 115 on the main. Bc I had just them them laying around with no changes. I might have to looking into a kit. But it ran great with the k@n the stock main awhile back for a few thousand miles, plenty of power, sounded good, and ran smooth. That’s how I bought it. Sometime last year it was acting up and from there I’ve been replacing all things I could think of with no change whatsoever.

[posplayr]

If you let the carbs dry out your pilot jets can get plugged and it will not idle or run unless you are 1/2 throttle or above.

[Gunner]

I went through them yesterday, and sprayed everything down again. All coming out where it’s suppose too. Bowls were still spotless from my last cleaning. Would some kind of going out bearing cause slight hang ups without load. But it’ll probably be noisy? Right. I have no abnormal noise. Once you get above 3,000 rpm it does fine until the load is gone. And been through the carbs so many times I’m not convinced it’s the problem. It hangs ups for a second and then catches itself. But the afterfire keeps pointing me to fuel/air problem.

[steveb922]

Has it run well since you fitted the fuel filter?

[Gunner]

It always had one, I just put a new one on thinking it might solve the problem.

[steveb922]

They can sometimes be a problem, but it sounds like the filter is not your particular problem. If you wanted, you could eliminate the filter as a possible cause by trying to run the engine without the filter - just a straight fuel line.

[Gunner]

They can sometimes be a problem, but it sounds like the filter is not your particular problem. If you wanted, you could eliminate the filter as a possible cause by trying to run the engine without the filter - just a straight fuel line.

Ill try that. I’m open to any opinions.

[Gunner]

Is it outlandish to think many something internal besides timing and valves could be the problem?

[posplayr]

Is it outlandish to think many something internal besides timing and valves could be the problem?

If it ran before then it is unlikely there is anything internal from keeping it running.

If you think you have the carbs together right make sure you have good voltage to the coils and a blue spark as opposed to weak yellow spark.

You can check the static timing even if it is not running.

It is possible the igniter is acting up but checking for spark should confirm/deny that.

[Gunner]

It ran good for 6 months and starts doing this, all these parts and tinkering were after it started running rough. But I will check everything twice again along with the valves and see what I come up with.