Suddenly not starting

[DevilsAdvoduck]

After sitting for two weeks, my GS doesn’t want to start or run. I can get it started with starting fluid, but then doesn’t want to idle and bogs at around 5-6k. T will only run if I have the throttle open and keep it above 2500.

It was running well a couple weeks back, but had to keep it parked while I waited for some parts to come in. All the work I’ve done since it was running had been either cosmetic or on the clutch and secondary gear.

so far I’ve tried:
- checking valve adjustment
- verifying choke circuit is clean and clear in carbs
- fresh battery charge
- inspected wiring connectors
- fresh gas
- verified petcock works (both by using spare hose and running into a cup and by pulling the carb bowls to make sure they were filling)
- checked carb float height
- verified spark on all cylinders
- checked gas cap venting


Other background: I am running APE pods, a Djelkevic 4-1 exhaust. Dynojet stage three kit, bench and vacuum synced. Carbs were fully disassembled, dipped, cleaned and all passages cleaned as per the guides on here. New o-rings in carbs. Carb boots o-rings are new.

I haven’t checked compression since the problem started since I haven’t been able to warm the engine, but I did test three weeks ago before the vacuum sync and all numbers were within manual specs.

if anyone has any ideas or suggestions on what else to look at, I’d appreciate it. Thanks!

[LAB3]

It was running well a couple weeks back, but had to keep it parked while I waited for some parts to come in. All the work I’ve done since it was running had been either cosmetic or on the clutch and secondary gear.


if anyone has any ideas or suggestions on what else to look at, I’d appreciate it. Thanks!

About the only thing that comes to mind is what would working on the clutch and secondary gear has in common with the fuel and electrical system. My guess is things needed to come apart and be put back together during this process so if it where me in that position I'd go over all the stuff I might have put my hands to get that work done.

You also gave us a list of things you've already tried, rarely do I see people mention checking the resistance of their spark plug caps, they should be 10k ohms. Also, taking them off the wires and clipping a 1/4" or so of the wire off helps assure a better connection upon reassembly. Like I said, it's very commonly overlooked!

[rphillips]

I'm thinking a problem with more than 1 cyl. won't one of these eng. easily start and run if one cyl. was completely dead?

[DevilsAdvoduck]

About the only thing that comes to mind is what would working on the clutch and secondary gear has in common with the fuel and electrical system. My guess is things needed to come apart and be put back together during this process so if it where me in that position I'd go over all the stuff I might have put my hands to get that work done.

You also gave us a list of things you've already tried, rarely do I see people mention checking the resistance of their spark plug caps, they should be 10k ohms. Also, taking them off the wires and clipping a 1/4" or so of the wire off helps assure a better connection upon reassembly. Like I said, it's very commonly overlooked!

Definitely didn’t check that. Thanks for the idea! I’m not hopeful that’s the issue. They are new cables and caps. I’m using non suppressed wires but BR8ES plugs. I’ll test and let you know.

Thanks again.

[LAB3]

Definitely didn’t check that. Thanks for the idea! I’m not hopeful that’s the issue. They are new cables and caps. I’m using non suppressed wires but BR8ES plugs. I’ll test and let you know.

Thanks again.

BR8ES is a resistor plug so you should be running non-resistor caps with those. Like you I doubt that's the issue but it's nice to get it right and not have to think about it again.

[DevilsAdvoduck]

BR8ES is a resistor plug so you should be running non-resistor caps with those. Like you I doubt that's the issue but it's nice to get it right and not have to think about it again.

I was gifted a set of new non resistor caps and wires so i went with these plugs. Caps and wires tested out fine.

I having second thoughts about the petcock. When I synced, I was using a feeder bottle. I ran for maybe 3-4 mins before my secondary drive decided it had lived long enough. I checked it and seemed like I was getting good flow. I’m grasping at straws at this point so I might just get a new one on there just to completely rule one more issue out.

[LAB3]

You could always try to test the petcock by seeing if it flows into an empty container while in the prime position then try it it in the run position by sucking on the vacuum hose.

[DevilsAdvoduck]

Brief update: I found one possibly loose connector from the ignitor to the right side coil. Not sure if it was loose before or if I pulled it accidentally in my last wiring run down. Replaced the connector anyway since if it was that insecure I’d rather it be gone. We will see tomorrow since it’s after 9pm and my neighbors don’t completely hate me yet.

I’m also wondering if my fuel line may be contributing. Since I switched over to a G tank and ditched the L, the petcock is in a different spot so there’s a bit of an extreme angle on the fuel line. It looks like it should flow, but might as well try it. That would explain why it ran well on a feeder bottle since the line would have been straighter.

[Rijko]

Tank may have water, dirt or rust inside, which may now be in your carbs ..

When encountering issues, if possible, i always go back to a "working" situation.
Will it run right on a feeder bottle now ?

[DevilsAdvoduck]

Cleaning up the connector from the ignitor to the coils seems to have done it! Or this is the beginning of an intermittent issue, we’ll see.

Thanks everyone for the suggestions and advice! Plates and tags should be here on Monday so only around the block shake down runs until then.

[rphillips]

You're gett'in there. Congrats & hope it's done.

[oldGSfan]

Just saying, for the remote possibility and as a head's up: I had two bikes, GS1000 and CB750 stop running. One sputtered, coughed and quit. The other would run but badly. I did a lot of troubleshooting then remembered that I had put fuel in both of them from the same place and then parked them a couple of weeks. I put in 'Dry Gas' or was it 'Heet'? Whaterver, both cleared up in a few minutes.

[DevilsAdvoduck]

Just saying, for the remote possibility and as a head's up: I had two bikes, GS1000 and CB750 stop running. One sputtered, coughed and quit. The other would run but badly. I did a lot of troubleshooting then remembered that I had put fuel in both of them from the same place and then parked them a couple of weeks. I put in 'Dry Gas' or was it 'Heet'? Whaterver, both cleared up in a few minutes.

I’ll keep that in mind (hopefully not) for the future!

[Rob S.]

Do we know what model we're talking about?

My 11EZ always became cranky about starting after sitting more than 2 weeks. A fully, fully, fully charged battery helped.

[DevilsAdvoduck]

Do we know what model we're talking about?

My 11EZ always became cranky about starting after sitting more than 2 weeks. A fully, fully, fully charged battery helped.

Sorry, thought that was in my signature but doesn’t look like it’s there anymore. It’s a 1980 GS1000L.

I tried both charging the battery that’s on the bike as well as a freshly topped off other battery that I had on hand but that wasn’t it. Seems to have been a wiring issue. First longer run will be early next week so we’ll
see what other bugs pop up.