It sounds to me like you found your problem... Test the coils primary and secondary resistance just to be sure, but I bet that's your problem....


Primary resistance should be 2.6 - 3.2 ohms @ 68 degrees F
Secondary resistance should be 13 - 17 K ohms @ 68 degrees F



EDIT: Sorry, I just assumed that you had a GL1500... If you have a different bike, then the specs most likely will be different.

 

since you swapped the coils and discovered the problem is a bad coil i'd say you eliminated alot of guess work. i don't think oem coils are available but you can try ebay (50/50 shot at best they are good), bike salvage yard, or post in the wanted section here. some have had success with the dodge neon coils while others use the ones from the honda CBR's. going that route, you'll be doing some fabricating on the brackets.

 

i have a 1985 gl1200i
i will check my book for exact impedance before spending a lot of money.

 

I think you will be fine just doing some eBay coils.
I would suggest you get the same year as the wire ends changed.

 

What bike Dwayne? If it was me I would be doing a coil swap for updated coils off another vehicle. There are many post on this subject, I would also install a relay to supply the coils.

 

Okay to my dismay i bought coils tested them with my meter and installed them still no good. I thought i saw a posting for electrically testing the PGs i did the resistance test and they are both at around 340 ohms. Does anyone have a link to the discussion i am talking about i will also keep looking and will add it when i find it

Here is a link with very good info
http://goldwingdocs.com/forum/viewtopic.php?f=5&t=1397

http://gl1200.free.fr/index3.htm

 

Okay to my dismay i bought coils tested them with my meter and installed them still no good. I thought i saw a posting for electrically testing the PGs i did the resistance test and they are both at around 340 ohms. Does anyone have a link to the discussion i am talking about i will also keep looking and will add it when i find it

Here is a link with very good info
http://goldwingdocs.com/forum/viewtopic.php?f=5&t=1397

In your first post you said you switched the coils and the problem followed. That pretty much concludes a bad coil. BTW an ohm test is not reliable most of the time, on either the PGs or coils. Take the original coil you had that was firing and the one you bought that was firing and try those.
And yes the will run on 2 cyls.

 

Got another question may not matter but. in most of the postings i have read about people with 2 plugs not firing. the bikes don't seems to start at all and if they do the bike die shortly after and they are hard to start. In my case the bike starts with no hesitation and after it warms up it will idle. when i ride it doesn't really give me any problems other then it seems very sluggish. Is it even possible for a bike to run on only 2 plugs. I mean i know i don't see spark when i test them but after reading all these posts i am stating to second guess my findings.

 

my 68 plymouth 318 was running on 2 cylinders for 6 months when i drove it onto the flatbed and sent it to the scrapyard.

 

Now what you are describing sounds more like the pulse gens.
Did you test them?

 

DaveO430
I will try tomorrow to get the screws out of the use coil set that I bought the screw stuck pretty good so I have rounded out 2 of the heads.

Bike...and Dennis
I did the ohm test but have heard more then once that this is not a good test of good or bad. Is there a better test that you k now of for testing the PG’s


Thanks to everyone for all this help

 

So i looked at the ECU and the vac line to it was not attached and also cracked. the other end of this line is attached to the bottom of the (air purge valve) but has no clamp not sure that matters here are some pictures input would help.

http://www.flickr.com/photos/25381948@N06/sets/72157633901631279/


Update: not sure if this mattes but after looking at the schematic for the ECU it looks like it either controls the tachometer or the tach is simply wired though it. my Tach seems to work only when it wants to. I have scoured the threads looking for analog tach problems but can only find digital. I have a 85 gl1200I with analog read out do these hooked up the same as the LTD and ASPY as far at it is not controlled by a cable but is controlled by a sensor, and if is is a sensor is it controlled by the ECU

 

Update: not sure if this mattes but after looking at the schematic for the ECU it looks like it either controls the tachometer or the tach is simply wired though it. my Tach seems to work only when it wants to. I have scoured the threads looking for analog tach problems but can only find digital. I have a 85 gl1200I with analog read out do these hooked up the same as the LTD and ASPY as far at it is not controlled by a cable but is controlled by a sensor, and if is is a sensor is it controlled by the ECU

This is the way it works.

You're pulse generators send a signal to the control unit.
Based on this input, the control unit operates different components.
Both coils, fuel pump relay, and the tach. The control unit provides a ground for the right coil (1,2). It also provides the ground for your tach. If you are losing the right coil, and the tach, the problem lies in the control unit or the pg's and/or the connector.
The hose that provides the vacuum signal to the control unit goes to the ported vacuum source on #4 carb ONLY. If it's routed somewhere else, it's wrong.

 

glhonda:
Thank you for the explanation i will pull the carbs to verify vac routing if i don't find anything wrong with the ECU connectors. i may just pull the connectors and hardwire everything

 

The 1200 is prone to pg failure. Not control unit issues. The pg that provides the signal for the right coil/tach is most likely fubar. As Dennis said, this is most likely a pg problem.

 

So have been looking through the threads because my front 2 spark plugs are not firing.I found a lot so i began by doing a voltage test the PG'S and got 12 volts as i should have, i swapped the coils and the problem followed the coil to the rear plugs. So (1) did i do the right thing swapping the coils or did i complicate things. (2) I am also thinking about just replacing both coils since i am in the bike anyway.(3) has any one had better or worst luck with aftermarket coils vs factory.

Thank you
Dwayne

I'm not super familiar with the design of this particular ignition system, but it does sound similar to the GL1500's. (in which case, I doubt that one PG fires the right coil, and the other fires the left, as the GL1500 also has 2 PG's but it has six cylinders and 3 coils) The pulse generators are for giving the CPU crank position input, it's not a direct firing mechanism. The CPU takes that information and it makes the decision as to which cylinder is going to fire, and when. It's an older system than mine, but this is generally how they work.

The thing I see here is that the problem followed the coil when you swapped it. Did you check all 4 plugs, and see spark in 3,4 but not 1,2? Then swap it and it was the other way around? It's possible if you're visually checking that you actually do have spark in all 4 cylinders and just can't see it very well. ( ie: testing in outdoor or bright lighting conditions. I went through this recently with my bike. It was sparking, but the spark was somewhat weak, and I couldn't see it out in the driveway where I was working on it.) New plugs made a world of difference in my situation. The fact that the bike runs, but only seems a little sluggish would tend to support this. If you were running only on two cylinders, it would be very rough all the time.

Hope this helps.

Doug

 

So the first test was I pulled each plug and tested with the cable it came from. only got spark on 3 and 4. So i swapped spark plugs and still same results. then i swapped the input to the coils (swapping the coils) and the problem moved to no spark in 3 and 4 had spark on 1 and 2. replaced the coils and has the same problem no spark on 1 and 2. all test were done in my garage.

I have already ordered new pgs but am still looking into other possible causes before they arrive.

 

From the gl1100 service manual: There is one pulse generator and one transistorized spark unit for each pair of cylinders.
From the gl1200 service manual

You will notice the pg's are wire color coded yellow and blue.
At the control unit the coils are yellow/tracer and blue/tracer. Yellow (1-2), Blue (3-4)
Below is a picture of actual pg's for an '85 gl1200. Notice they are wire color coded yellow, and blue.

From the gl1200 service manual you'll see the same yellow color coded pg labeled as No.1,2 pulse generator.

So as it turns out, one pg signals for operation of one coil, the other pg signals operation for the second coil. In this case, the yellow 1.2 pg signals the right side coil.
Since the coils have been replaced, it's not a coil issue. Since the tach doesn't work correctly, it would indicate there is a problem on the 1,2/right/yellow circuit.
Since control units fail very very rarely, and pg's are notorious for failing, check the air in the tires.

 

My bad. Sorry, I didn't catch the part about the tachometer working only when it wants to.

 

Not sure which of my tools to use for that tire pressure test LOL

Thank you for that diagram

 

It is very important to check pressure after a known fill up of Summer, not old Winter air within the tire.

 

I think the temperature of the air might be more important than the pressure!:ROFL:

 

update

Okay so i installed the new pgs still same problem. swapped right coil with a known good coil same problem. removed all plastic connectors still no dice. got a used ecu from ebay and i now have spark on all 4. will update once i get the bike back together.

 

Update !!!!!!

bike started up sound great. corrected idle since it was set with only 2 cylinders firing. But to my dismay i have no clutch. On the hunt for the fluid leak.

 

Update!!!!
bled the clutch working great. now rear brakes spongy after a 45min ride. guess i know what i am doing tomorrow

New
Got the brakes bled. took the bike out after sitting at 2 innercity stop lights she started to over heat hope it's only that i need to burp it. will fibd out after she cools off

 

Okay after a few really stupid mistakes I got the coolant system burped. I left the cap off a little too long and the coolant started boiling before i for the cap back on. then i turned the bike off with the coolant boiling with out the rad cap on and of course the system tried to pressurize and it just flowed right on out. Waited for it to cool off topped it back off and burped it. i took it for a nice long ride about 100miles round trip. it has not over heated but when i stop at lights she heats up to just to the left of the blank spot before the red overheat. as soon as i start riding again the temp will start coming back down slowly. any ideas.

just for information i have the poorboy system installed so i know it will run a little warmer with the fan blades so close to the rad just not sure how warm is normal with this system installed.

 

You really need to list what bike you have in your signature Dwayne. Year and model.
I'm guessing from your description of the gauge that it's an Interstate, after going back to the original post that it's a GL12. Seems like it would be easier if we could just read that somewhere on each post.
Anyway, if my sluething skills payed off, and it is a GL12I, the needle readings sound about right. As long as the fan is kicking in, you're OK.
Oh, and I don't see how the fan can be a different distance from the radiator. The fan housing bolts directly to the radiator.

 

Thank you
Yes you are correct it is a 1985 gl1200i. And the fan is closer to the rad because when i installed the poorboy alt kit i had to cut one fan support off and bend the other 3 so that the fan blades don't hit the belt.

 

If it turns out you need new coils

I would UPGRADE to GL1500 coils.

I bought my GL1500 coils from Ebay.

Get the coils from a GL1500.

They are heavy duty, and have a hotter spark.

I paid $35.00 ship was free.

I Bought the GL1500 coils with the spark plug wires and i used the GL1500 Coils and spark plug wires on Both my 83' GL1100

and My 86' GL1200