I think 2 cylinders are not firing


Information and questions on GL1200 Goldwings (1984-1987)
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scrbowler
Posts: 18
Joined: Wed May 05, 2010 10:07 am
Location: Blanchard, OK
Motorcycle: 1986 GL1200 Aspencade

I think 2 cylinders are not firing

Postby scrbowler » Thu Jun 10, 2010 1:18 pm



It's an 86 Goldwing Aspencade. I have it running after some cleaning and maintenance but it seems that the right side cylinders (1 & 3) are not firing. I feel we have it down to one of two things but that is from my less than experienced mind of a new goldwing owner. While the bike is running we pull the plug wires from the #1 and #3 cylinder and neither one makes the engine change noise or anything which is why I believe they are not firing.
1) not getting enough fuel to those two cylinders. We pulled the plugs from all cylinders and the #1 and #3 both have a dark, wet residue on them. Not a lot of moisture though which is why I think there is only minimal gas entering the cylinder. I took loose the gas line from the fuel pump and it is pumping plenty of gas. I have removed the fuel filter also just to make sure the flow there is good.

2) the coils may be bad. I have no idea how to check these to see if the problem lies herein with the coils but it just seems like the spark when checking the #1 and #3 cylinders is much weaker then the #2 and #4 cylinders. Any input on this would be good too.

Lastly it seems that we are still having a charging problem even though we have replaced the regulator and checked the stator output and verified it to be good. Not sure if the same problem could be the issue with both charging and non firing cylinders or not.

thanks in advance for your input.
Steve in Oklahoma



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WingAdmin
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Location: Strongsville, OH
Motorcycle: 2000 GL1500 SE
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Re: I think 2 cylinders are not firing

Postby WingAdmin » Thu Jun 10, 2010 3:06 pm

First off: You can damage the coils on a four-cylinder Goldwing by removing plug wires while the engine is running. If anyone cares to know why, I can explain it, but you should know that because of the way Goldwings use two coils for four cylinders, pulling the plug cable off a plug while the engine is running can cause the failure of a coil.

Secondly, there are two coils for four cylinders:

4 Cylinder Wing Coil Wiring
4 Cylinder Wing Coil Wiring


Therefore, if one of the coils was weak, it would be cylinders 1 and 2, or cylinders 3 and 4 that would have weak spark, not 1 and 3.

That is why I will go with your first supposition: not getting enough fuel to the two cylinders in question.

Also, just to be sure, when the engine is cold, start it up while putting your hands on the exhaust manifolds coming from each cylinder. You will be made aware very quickly which cylinders are running and which are not.

If you have an infrared thermometer ($15 at Harbor Freight) you can run the bike to normal operating temperature and point the thermometer at each of the exhaust manifolds, one at a time. If a cylinder is running poorly, it will be significantly cooler than the others.

scrbowler
Posts: 18
Joined: Wed May 05, 2010 10:07 am
Location: Blanchard, OK
Motorcycle: 1986 GL1200 Aspencade

Re: I think 2 cylinders are not firing

Postby scrbowler » Thu Jun 10, 2010 4:12 pm

Thanks for the warning on pulling plug wires while the bike is running. I did not know it could do possible harm to the coil.

The bike runs and seemingly smooth but seems low on power (similar to the bike being geared way too high and it takes some clutching to get rolling) and the plugs show differently on the right side than the left side. There is more of an almost lean condition on the left side with plugs showing just a shade lighter than the optimal golden look. And there is still some backfiring going on which I assume is from the dirty carbs and the enviroment they cause in the bike. One thing that is confusing is the pipe on the right side at one time became so hot it turned it blue and that is the side I question about firing or at least weak.

My first step is to pull the carburators off and make sure it is clean and the jets are clear. I can't imagine that the coils would fire one cylinder and not the other with both coils acting the same so that will wait till I make sure each cylinder is getting fuel first.

thanks again, I will keep you posted on my progress.
Steve

scrbowler
Posts: 18
Joined: Wed May 05, 2010 10:07 am
Location: Blanchard, OK
Motorcycle: 1986 GL1200 Aspencade

Re: I think 2 cylinders are not firing

Postby scrbowler » Thu Jun 10, 2010 11:16 pm

OK, you are never going to believe this. After gathering all the intel I could about the bike and the issues I have been dealing with I got to checking and surveying all the parts and wiring and whatever while I fixed a broken connection into the regulator I found last night.

Now the good part. We went to start the bike again to check if the right side cylinders were firing and we had no fire at all. You can imagine my "What the........". Well in checking everything from the plugs getting fire to tracing more loose connections we discovered that the plug wires on the right side of the bike had been reversed at some point. They had been that way all along which was the main source of most all our issues. After finding a loose connection in the wiring harness we were back in business and the bike runs like a top. Lots of power and get up and go. Now if the charging system is working properly then I think all is well and we'll be back on the road again. I feel so stupid to not notice the plug wires in the first place but I'm going to just chalk it up to experience.

thanks again for everyone's help in diagnosing all of our issues. It is much appreciated.

Steve

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WingAdmin
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Posts: 17050
Joined: Fri Oct 03, 2008 4:16 pm
Location: Strongsville, OH
Motorcycle: 2000 GL1500 SE
1982 GL1100A Aspencade (sold)
1989 PC800 (wife's!)
1998 XV250 Virago (sold)
2007 Aspen Sentry Trailer

Re: I think 2 cylinders are not firing

Postby WingAdmin » Fri Jun 11, 2010 9:59 am

Yup, that will definitely cause those cylinders not to fire! I'm surprised you weren't getting backfiring and other nonsense going on. Glad to hear it's running well now, though!




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