spark fuel ? Update 11-30 yanking the carb

[Omega Man]

Gotta ignition or carb problem this afternoon. Got ready to leave for home a little while ago and she was missing bad but idled fine, didn't even come close to stalling. From 1500-2500 rpms runs rough needing more throttle, then something happens and shes' climbing to 4500 rpms. I can hear the rough sounding miss while cruising but it doesn't affect cruising much. When I let off the throttle she does not nose dive but cruises to a lower speed like normal, again without threatening to stall. I was much lower on gas than I usually get. Can one cylinder cause this, like a bad plug?

Any ideas?

~O~

 

[AApple]

From the description, I would lean towards it being an iggy issue. Possibly a coil on the fritz? Sparkle plug wire shorting somewhere?

 

[Omega Man]

Thanks Jerry! I just needed a place to start. The plugs will be checked first, but even though I have really no understanding of how the coils work, that was really the first thing that came to mind. Then again a shorting wire is not out of the realm of possibility.

Anyway thanks bro. :good:

~O~

 

[slabghost]

My Valk does that when I forget to open the petcock. It seems to pull enough to keep running but not enough to run right.

 

[pidjones]

Failing fuel pump/lines collapsing/poor tank venting?

 

[Omega Man]

Thanks again guys, more to check this weekend.

~O~

 

[Ian38091]

I had problems something like this when the carbs on my gl1000 had blocked filters at the float valves causing fuel starvation. Might be worth considering. Had to strip the carbs to fix it.

 

[Ansimp]

My mate was chasing a gremlin in his CB1300 with a similar style miss/flat spot on low-mid revs. Finally sent it off to a dyno tuning guy for diagnosing ($100 flat charge) and came back with 4 new plugs for $111 total. Job fixed! :doh:

 

[Omega Man]

These plugs were changed when the belts were done... about four years ago. I'm checking that later, decided to mow the lawn first today(first time in 35+ years). I'll bet one was bad already but I couldn't tell, I've heard this about the 1500s.

~O~

 

[Omega Man]

No spark on the right side of the engine. I'm wondering if the clutch hose fiasco some how might have caused this. Anyway, my time here has me thinking it's now something to do with the corresponding coil.

Need advice, ty.

~O~

 

[Omega Man]

Hmmm, read there are three coils, so if all three plugs on right side of engine all three coils went bad at the same time? :nea:

Sounds like I'm in for another nightmare R&R. I couldn't believe my eyes, "the carbs must come out as do the radiators." :sensored: :head bang:

~O~

 

[Ansimp]

Just put some new plugs in before you do anything else, cheap diagnostics.

 

[dan filipi]

Agreed. 6 new plugs and run it. Real strange things can happen on a wasted spark system if the opposite plug on the same coil is also bad.

 

[Omega Man]

:head bang: She has 6 new plugs installed just a while ago tonight.

~O~

 

[Omega Man]

I did the pull the plug wire test when I found out the right side is no spark.

~O~

 

[dan filipi]

Sorry, I can’t help much from here bro other than check all your fuses, wiring at the fuses, and all the wire harness plugs are plugged in tight, and connections are clean. I don’t know where the ignition pickup coils are, but check those wires and plugs also.

 

[joedrum]

hmmm i dont know much on 1500 iggies ...

 

[desertrefugee]

This is not making sense. The 1500 has complete GL DNA. The cylinders are numbered the same way:

2......1
4......3
6......5

Like the 4 cylinder bikes, the coils drive pairs of cylinders. 1-2, 3-4, 5-6.

Pulsers are also paired with consecutive coils. So, electrically, I can't see anything that would affect just one side of the bike. Unless something in the harness has been physically damaged, this really is a mystery. Has there been any recent work under there that might have disturbed the harness? Sorry, but that's all I have for now. Been poking at this one, but it really doesn't make sense.

 

[Omega Man]

desertrefugee » Sat Oct 27, 2018 8:33 pm[/url]":2gppstp6]
This is not making sense. The 1500 has complete GL DNA. The cylinders are numbered the same way:

2......1
4......3
6......5

Like the 4 cylinder bikes, the coils drive pairs of cylinders. 1-2, 3-4, 5-6.

Pulsers are also paired with consecutive coils. So, electrically, I can't see anything that would affect just one side of the bike. Unless something in the harness has been physically damaged, this really is a mystery. Has there been any recent work under there that might have disturbed the harness? Sorry, but that's all I have for now. Been poking at this one, but it really doesn't make sense.

Yep, the clutch hose from HELL. I had to jam it in and out about 200 times until it came "up" in front of the engine instead of "down." That was on the left side of the engine though, still could have messed something up.

~O~

 

[Ansimp]

Aren’t there 2 carbs on the GL1500 each one feeding one side of the engine? Fuel is the only thing that can stop one side in my opinion.