running on two cylinders

[Guest]

1980 GS1000G
Hey everyone, I am out on an early season ride in Colorado. Yesterday while I was riding I lost power, but not all power. When I stopped I checked my exhaust pipes, and 1 and 4 were barely warm, 2 and 3 were hot as they should be. So I am running on two cylinders only. Can I assume that the problem is the ignition coil, or are there other possibilities for 1 and 4 to go out at the same time? The bike still runs and starts, I was able to limp on to my destination, but it was using a lot of fuel.

Since I am on the road I don't have my books with me, so I have a few questions:

If it is the coil, does anyone know the ohm resistance for these coils?
Can you recommend a certain aftermarket, or is it important to go oem?
Should I replace both coils while I am at it?

Thanks in advance for any and all help!
Mark

[Brendan W]

Primary should be in the 3 - 5 Ohm range and the secondary 10 k ohm or more. Compare both coils they should be the same.
Coils are fairly bullet proof. I'd say it's more likely you have a supply problem to that coil. Plug under the tank is a usual suspect.

[gsnewbie68]

Have you checked for spark on 1&4? My thoughts are burned points if its a points system or coil went out personally I'd replace both at one time .

[gsnewbie68]

Good point also check for voltage to the coil before you condem it

[geol]

Step one is to check voltage to the 1&4 coil... if the pipes appear to be just warm, those cylinders are not firing and the warmth is picked up from 2&3.

if voltage, then the coil is likely dead. If no voltage, keep in mind that the voltage going to 2&3 is just one leg off a split so the problem of no voltage will be the connector under the tank or the orange/green connected to the coil has come off or is loose. If there is power:

Step two is to check the 1&4 coil by swapping with the 2&3.

If the problem moves to the 2&3 cylinders and 1&4 now fire, then the coil that was originally on 1&4 is bad and needs to be replaced. If the problem remains, your IC electronic ignition wire for 1&4 may have come loose, the IC igniter connection to that wire may be loose, the Ic Igniter may be back or perhaps the 1&4 side pickup coil is bad. Try and fix any loose connection but if the connections are good, the ignition should be replaced (think Dyna S).

[rippledub@gmail.com]

Thanks for all the suggestions!
I'm no pro with the meter, but I think I can figure out the basics here.

One Question, If both the 1 and 2 stopped firing at the same time can that be the points? Wouldn't one go out at a time? I remembered from rewiring my coils that each one handled two plugs, that's why I assumed coil. What don't I know about the points? (many things!!)

Ill get a meter and start checking things . . . thanks again, and I will post again if I run up on any other questions!

Mark

[gsnewbie68]

If your running on a points system like mine the top set controls the #1&4 & the bottom set controls #2&3 but I'd only mess with them only after you have ruled out the voltage at the coil the points ground out the coils completing the circuit thus building voltage in the primary winding of your coil once they open they break connection causing the voltage to run through the secondary winding I forgot what the term is called off hand but suffice it to say the voltage increases exponentially and fires the plug.

[rippledub@gmail.com]

Turns out it was a broken wire at one of the solder points on the coil.

Thanks for your help everyone!

back on the road.

mark

[IRONKICKER]

Good day - New to this forum and have been reading - Working on a 82 GS1100GL - Started with helping a young fellow at work and turned into a obsession to get it running correctly - Was setting for 12 years and he bought it from his uncle - cleaned carbs and got running, was blowing main fuse and found and replaced bad rectifier - I can get it running but 1 and 4 are for the most part dead - can get a bit of life by covering air passage in carbs. due to the problem cylinder are on the same coil pack would like to check/swap before going through the carbs again - spark does look good w/ a in line tester installed on dead cylinders - My question is when you say " check the 1&4 coil by swapping with the 2&3 " I did swap 1 to 4 coil pac to 2 to 3 cylinder - no start at all ----are you talking just the wires going to plugs or do I also need to swap wires going to coil pac - Thank you Ron

[BigD_83]

Probably would be better to have your own thread on this new to you problem.

You need to swap the wires supplying electricity to the coils.

[IRONKICKER]

Got it and will do Thank you Ron