Running on 3 cylinders - then misfire

[Terje Treff]

82’ GL1100 Standard. 8k miles at time of purchase. Rode a couple thousand miles with no problems whatsoever. Then it started what felt like it was running on 3 cylinders. Occasionally at first, and over time developed to a permanent problem. Replaced plugs, coils, caps, and wires. Now I get a brutal misfire when giving throttle, even if it runs perfectly at idle. Seems to appear after warming up.
Any advice ?

 

[saganaga]

Have you checked compression at all? If so, then I'd suspect the carb, assuming you've verified a spark in the "missing" cylinder.

But I could very well be wrong, I'm not an expert.

 

[joedrum]

Sheesh what do they call those dang things on 1100s ignition sparkers there are two of them...in the shelter...sounds to me that what going on ...seems like one is getting hot and throwing out bad sparks

 

[Terje Treff]

joedrum » 2019-06-09- 6:50[/url]":2c8box53]
Sheesh what do they call those dang things on 1100s ignition sparkers there are two of them...in the shelter...sounds to me that what going on ...seems like one is getting hot and throwing out bad sparks

Coils ??

 

[joedrum]

No not coils ...it’s part of the cdi ignition Honda switched too after they drop the points ignition system that on 1000 wings....but there are are two of them like there are coils also ...there in the shelter under the false tank ..it would have to come off to get to it .....but for sure it sounds a lot like the condition your bike is having ....they can work fine when cold but as they get hot can start cutting out ...it could be just one doing it ...maybe someone will post a pic of one ...

 

[desertrefugee]

I'm with Joe. For sure it sounds electrical. Would be helpful to determine which cylinder is misfiring. Inspect the plugs. Look for one that stands out.

The plug read could really drive your next steps, but swapping coils, the plugs themselves or reattaching the caps after trimming off some wire might not be a bad idea. One bad plug wire can ruin your day.

 

[chilidawg]

When you say it "felt" like it was running on 3 cylinders? Do you mean your normally revvy, powerful & torquey motor suddenly ran like a very heavy 50cc moped? Because that's what these bikes "feel" like running on 3 cylinders.

If it didn't feel like that, then maybe all you need is a carb sync, another symptom of needing a carb sync is a loud primary chain noise when pulling away from lights and stop signs, and some misfiring, if it's bad enough.

But hey! look on the bright side, you probably needed new plugs, wires and coils anyway!

I think Joe means these doohickeys?

 

[mcgovern61]

Those are called "igniters" and yes, if they overheat the insulating material will melt like tar from the back of them.

 

[Terje Treff]

chilidawg » Yesterday- 19:40[/url]"i13yo44]
When you say it "felt" like it was running on 3 cylinders? Do you mean your normally revvy, powerful & torquey motor suddenly ran like a very heavy 50cc moped? Because that's what these bikes "feel" like running on 3 cylinders.

If it didn't feel like that, then maybe all you need is a carb sync, another symptom of needing a carb sync is a loud primary chain noise when pulling away from lights and stop signs, and some misfiring, if it's bad enough.

But hey! look on the bright side, you probably needed new plugs, wires and coils anyway!

I think Joe means these doohickeys?

Definitely not like a 50cc moped, because it would still do highway speeds with little problem, but still significantly down on power. It didn't seem like a carb issue because it would cut in and out and could run perfectly for extended periods between the moments it lost power. Over time it just became more consistent until in the end it was there all the time. Although I feel like I've had some of the primary chain noise you mention occasionally.

After the replacement of coils, wires, caps and plugs, this particular problem "appeared" to be resolved (not completely sure, since I didn't get to do a proper test ride), but that's when the brutal misfire showed up to the extent it wasn't even driveable. Perfect idle, brutal misfire on throttle - but seemingly only after it warmed up. I may have caused something to go wrong when I replaced those other pieces I guess. Aside from that, I was happy to replace the coils, wires, plugs, and caps. It's a 38 year old bike, even if the mileage is low.

 

[Terje Treff]

mcgovern61 » Today- 8:58[/url]":1119i7ko]
Those are called "igniters" and yes, if they overheat the insulating material will melt like tar from the back of them.

I'll take them out and look at the back side.

 

[mcgovern61]

You replaced the spark plugs wires. Are you sure they are on the correct coil? Incorrectly swapped plug wires will allow the bike to idle but misfire big time when throttled up.

 

[Terje Treff]

mcgovern61 » 57 minutes ago[/url]":1mrtslnz]
You replaced the spark plugs wires. Are you sure they are on the correct coil? Incorrectly swapped plug wires will allow the bike to idle but misfire big time when throttled up.

I thought about it but it was taking throttle fine until it warmed up.

 

[Ansimp]

Too tight valve clearance can provide a slight misfire or performance drop

 

[GTC@MSAC]

Just throwing out a guess, but I've had many bikes with this symptom, and it almost always turns out to be fuel mixture, usually from stopped up or restricted passages in the carbs.
Bad pickup-coils for the ignition can be bad, but not as common as dirty, obstructed, or violated carbs. And bike mileage never seems to matter as much as age, and the fact that no matter the mileage, I seem to never be the first inside the carbs. I once even found someone drilled out the main jets with a 1/8 drill bit thinking "more gas means more speed" or whatever, lol!
I generally end up with bikes someone has given up on due to a variety of reasons, but carbs are virtually always a problem, and our new friend "ethanol"
has done some really crazy, bad things to carbs here lately.
So, yeah, my suspect is the carbs, lol!

Randaak's Cycle Shack has great custom made carb kits for GL1000 and GL1100, and GL500/650 with Viton seals and o-rings that are more ethanol resistant. Randall Washington has helped me immensely with stuff for my Goldwings and Silverwings!