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Coil to spark plug order? need help translating wiring diagram

  • Thread starter Thread starter bcoli
  • Start date Start date
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bcoli

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Question: Can anyone confirm the order that the spark plug wires should come off of the coils? I read on the forum that the cylinder order is (left to right) 1,2,3,4; but the previous owner had the spark plugs labels 1,3,2,4. This led me to investigate further and I may have the plugs out of order off of the coils. see attached pic.

I need help translating the wiring diagram. I'm not sure how to read the coils. In the diagram you'll see that I posted my current setup, as well as how I'm translating the wiring diagram. Can someone confirm? ty.

I recently picked up a really clean '79 GS850G. My entry-level mechanical knowledge has me thinking that the fourth cylinder may have a compression issue because the bike will run quite a while before stalling when the #4 spark plug cap is removed, and the header was "very warm" to the touch, not "melt skin" hot.

A valve clearance check is def in order. The #4 spark plug has a spark.
 
AS you sit on bike. the ignition coil on left fires #1 (extreme left) and # 4 plugs.
 
As Tom mentioned, the left coil usually fires the #1 and #4 plugs. I say "usually" because I got one bike that was "blessed" with an all-knowing owner who swapped the coils. The bike ran beautifully because all the wires were in the proper places, but the location of the coils was swapped.

It does not matter whether the upper or lower wire connects to #1 (or #4), they are electrcially the same. The spark plug caps will be a bit different for the inner and outer plugs. The outer plugs' caps will be shorter, the inner ones will be longer. The wires for plugs 2 and 3 also don't matter which wire goes to which plug.

.
 
I've had a bunch that had all sorts of numbering on them. Don't go by the numbers on the plug wires as they may very well have been messed with over the years. Just remember that plugs 1 and 4 come off the same coil as does 2 and 3. I believe that the coil that connects to the connector with the black/white wire goes to plugs 2 and 3
 
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one coil feeds the 2 outer plugs and the other coil feeds the 2 inner plugs
 
I think I have a related problem and I'm reusing this thread, please bare with me... my problem might escalate all the way to valve adjustment...(Exhaust valves maybe, I tried to be brief but just couldn't but Please Advise ! )

My story:

I got this 1983 GS 1100 GL has 8500 mi. (that's right less than 9k miles)
I cleaned the carbs, shinny freed jets, no leaks, floats leveled, new gaskets etc... all-in I'd say.
I tested the coils ( 3.2 and 3.4 Ohms)
this is not my first bike but I'm not an expert either... this looks like a bucket of gremlins I've been catching but I'm stucked with this one....

Bike starts right up, but running only on cylinders #1 and #3 ( 2 and 4 are dead cold )
I recall riding the bike with the old spark plugs and after a few laps around the block, all exhaust pipes were hot.

this happens no matter how I set the carbs ( 2 1/2 turns out, now 1 1/2 )
or even if I switch the coil cables.... 1to4 or 4to1, 2to3 or 3to2.
I just put new recommended NGK B8ES spark plugs, they all have spark, even the old ones had visible spark.

I'm very positive I can rule out carburation, All my floats have gas, all cv intake sucks enough to get my hand stucked on it and pull gas if I do so, all sliders are free and happy bouncing. Even if I had synched the carbs at high revs I'm guessing it wouldn't make any difference since I tried different configurations for the pilot air mixture screw. am I right? I know it's running lean now ( 1 1/2 turns out)

I'm also on the positive side I can rule out ignition timing since I got spark and no matter how I set the coils I cannot transfer the problem to the other cylinders. The symptom appears to be the same, I would say If only one coil was firing I would have cylinder 1 and 4 hot or cold ... in the same way 2 and 3 would be hot or cold but not mixed as I have it now... could I say is firing on time? Also, the bike will stumble and die if I remove any of the coil plugs from the spark plugs.

My conclusion and my fear is exhaust valves 2 and 4 are leaking? and somehow they work at high revs? as a low miles bike, I think they never serviced the valves, it's all stock all unmolested.
would anyone have another conclusion? thanks!
 
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I think I have a related problem and I'm reusing this thread, please bare with me... my problem might escalate all the way to valve adjustment...(Exhaust valves maybe, I tried to be brief but just couldn't but Please Advise ! )

My story:

I got this 1983 GS 1100 GL has 8500 mi. (that's right less than 9k miles)
I cleaned the carbs, shinny freed jets, no leaks, floats leveled, new gaskets etc... all-in I'd say.
I tested the coils ( 3.2 and 3.4 Ohms)
this is not my first bike but I'm not an expert either... this looks like a bucket of gremlins I've been catching but I'm stucked with this one....

Bike starts right up, but running only on cylinders #1 and #3 ( 2 and 4 are dead cold )
I recall riding the bike with the old spark plugs and after a few laps around the block, all exhaust pipes were hot.

this happens no matter how I set the carbs ( 2 1/2 turns out, now 1 1/2 )
or even if I switch the coil cables.... 1to4 or 4to1, 2to3 or 3to2.
I just put new recommended NGK B8ES spark plugs, they all have spark, even the old ones had visible spark.

I'm very positive I can rule out carburation, All my floats have gas, all cv intake sucks enough to get my hand stucked on it and pull gas if I do so, all sliders are free and happy bouncing. Even if I had synched the carbs at high revs I'm guessing it wouldn't make any difference since I tried different configurations for the pilot air mixture screw. am I right? I know it's running lean now ( 1 1/2 turns out)

I'm also on the positive side I can rule out ignition timing since I got spark and no matter how I set the coils I cannot transfer the problem to the other cylinders. The symptom appears to be the same, I would say If only one coil was firing I would have cylinder 1 and 4 hot or cold ... in the same way 2 and 3 would be hot or cold but not mixed as I have it now... could I say is firing on time? Also, the bike will stumble and die if I remove any of the coil plugs from the spark plugs.

My conclusion and my fear is exhaust valves 2 and 4 are leaking? and somehow they work at high revs? as a low miles bike, I think they never serviced the valves, it's all stock all unmolested.
would anyone have another conclusion? thanks!

Cut paste into a new thread; reference a link back to this link if you think it is relevant. This is someone else's thread.
 
posplayr, will do.

I'm figuring out the forum rules still and not sure if everyone would get an annoying notification if I post on this thread but if you do I apologize now.

Charlie G, Before I'd post the problem I wasn't sure what the solution could be, but after typing all the description in I'm more convinced and I agree with you. I'm skeptical someone would disagree with the valve job but lets also see if someone else got a magic spell that avoids it. hopefully this is helpful to more people. thanx.

next is the new thread.
http://www.thegsresources.com/_forum/showthread.php?p=2076331#post2076331
 
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