'79 GL1000 dead #1 & #2 sometimes

[Brownie]

My '79 GL 1000 runs fine on all cylinders when i start it up cold. After it gets warmed up, i sometimes get no spark on cylinders #1 & #2. If I wait a few minutes till it cools down, it starts right up and runs good on all 4. I replaced the points for number 1 and 2 with a spare set that i had and went down to fill up with fuel about 5 miles away. Bike ran fine all the way to the station. After fueling, i started back for home. About 200 yards from the station, the 1&2 cylinders failed to fire. I pulled of the road and waited a few minutes. Started back up and ran just fine on all four. Stopped to pick up the mail on my way. Turned off the ignition. Got the mail. Started up. Running fine on all four. Then as I approached the drive way to my home, cylinders 1 and 2 dropped off again. I am thinking this may be an intermittent heat-related
problem with the coil that controls 1& 2. Appreciate any help or suggestions.

Brownie
79 GL 1000

[ericheath]

Points or electronic? Dynas are known to begin dropping intermittently. Check wiring connections and grounds from points or Dyna to the coil.

[olchris]

Same same..

http://www.ngwclub.com/forum/viewtopic.php?f=1&t=58854

[robin1731]

Points or electronic? Dynas are known to begin dropping intermittently. Check wiring connections and grounds from points or Dyna to the coil.

He did say he replaced the points.

[RB]

coil with a crack..

[Brownie]

Thanks to all for your replies and suggestions. I do appreciate any help. I noticed on ebay a used set of coils for my GL and ordered them. I hope to try them when I receive and will post results. Of course I will check all connections at the same time as suggested.

Thanks again,

Brownie
79 GL1000

[tlbranth]

I'd check wires to 1/2 points to make sure they're not inadvertantly grounding at the connection. Also check the plug caps and wires. A break here could stop both plugs from firing. You could switch caps around to see if the problem moves.

[Brownie]

Thanks again to all who replied to my earlier post. I did receive the used set of coils and installed them. This has cleared up my problem so far. Since my GL has a Vetter fairing I had to remove it to be able to reach the coil mounts easily. To test it, I left the fairing off just to be sure all is working good before I button everything up. Let engine run until fully warmed up. So far no problems.
The only issue I am still working on is how to transfer the rubber grommet that holds to two spark plug wire together to the used parts I installed. The coils I received did not have the grommets on the wires. I don't want to damage any connections while transferring the grommets to the new(to me) wires.

Any suggestions appreciated.

Brownie
79 GL1000

[tlbranth]

The caps unscrew from the wire which allows the grommet to be installed. Then screw the caps back on.

[Brownie]

Thanks Terry, Got the grommets installed. But I think i may have disturbed a connection as my GL is not hitting on all cylinders now. I noticed that the connection to the spark plugs show a little corrosion. So I am combining some of the parts from my original coils and wires with the unit I installed from ebay. I will be checking it out further when I have time.

Thanks again for your help...

Brownie
79 GL1000

[robin1731]

Thanks Terry, Got the grommets installed. But I think i may have disturbed a connection as my GL is not hitting on all cylinders now. I noticed that the connection to the spark plugs show a little corrosion. So I am combining some of the parts from my original coils and wires with the unit I installed from ebay. I will be checking it out further when I have time.

Thanks again for your help...

Brownie
79 GL1000

Did you trim the wires before reinstalling the boots? That is pretty much a must. If you look at the end of the plug wire without the boot you should see good strands of wire. If not they can be trimmed back 1/8" or 1/4" to where you do have good wire.

[mrtwowheel]

Plug caps go bad, even intermittent like you described. There are 6 different electrical connections being made in a resistor cap, counting the resistor. They can be disassembled and cleaned, but more than likely the innermost connection will be so corroded that there will be no continuity at all when reassembled. I'm not complaining about these caps, they are a great design and have a great service life, but there is an end to that service life and new is better. Same with old copper core wires, metallic core wires with alloy core and silicone insulation is a great improvement over the old "small engine" wire.

Scott