Can both coils go bad at the same time???

[Jgolem]

I' hoping someone has a suggestion:
I am working on a 1986 GS550L trying to get it started. The last time it ran was a couple of years ago when it would begin to hesitate at cruising speeds. Each time I tried to start the bike it got harder and harder until eventually it would not start at all. Now, when I try to start the bike it just cranks over and does not start. I pulled all 4 plugs and they DO NOT spark AT ALL.

What I have done...I tested the signal generator and it was exactly within specs, so I tested the Ingniter and it did not fire the spark plugs, so I replaced it and still no sparks from any of the 4 plugs.

It seems as though I'm getting power to both coils. Is it possible for both coils to go at the same time? Anyone ever hear of that?

Jeff

[spyderrocs]

its probably the trigger

[Jgolem]

What's the Trigger?

I've never heard of that. What's the Trigger?

Jeff

[Road_Clam]

I' hoping someone has a suggestion:
I am working on a 1986 GS550L trying to get it started. The last time it ran was a couple of years ago when it would begin to hesitate at cruising speeds. Each time I tried to start the bike it got harder and harder until eventually it would not start at all. Now, when I try to start the bike it just cranks over and does not start. I pulled all 4 plugs and they DO NOT spark AT ALL.

What I have done...I tested the signal generator and it was exactly within specs, so I tested the Ingniter and it did not fire the spark plugs, so I replaced it and still no sparks from any of the 4 plugs.

It seems as though I'm getting power to both coils. Is it possible for both coils to go at the same time? Anyone ever hear of that?

Jeff

It's highly unlikely you have 2 bad coils. It's a common misconception to immediately fault the external coils because they are right there, and easily accesable. I can't tell you how many times I sold an external coil, and the customer came back a week later with the same no spark issue, as a result from assuming the coils were bad. More often I see bad CDI boxes, or faulty crank pickups. A dealer can check your external coils for correct resistance, and there is a simple test to check the crank pickup. If both are good, you have a bad CDI unit

[flyingace]

What is the condition of the battery? I would jump the bike from a NON-RUNNING car to see if it starts with enough juice. If not that, how about a running start? It's possible for a marginal battery to be able to turn the engine over, but not have enough juice left to fire the plugs.

[nabrams]

Definitely can't hurt to try to push start it but I'm with Road Clam on this one- very unlikely that both coils would go at exactly the same time.

[Jgolem]

RE: 2 bad coils?

Thanks for all the advice.
I have already replaced the CDI. By that I assume you mean the Igniter box. I bought one from Ebay. I know that's a shot in the dark, but it beat the $375 for an OEM part. Clymer says to check the Signal Generator (this is what I assume you mean when you talk about the "Trigger") via the Igniter box, which I did on both the new and replacement Igniter box. Both Igniter boxes read within specs for the Signal Generator (Should be between 200-500 and mine reads about 360). But each time I try the Clymer test to fire the spark plugs by way of touching probes to the Igniter boxes (both old and new) neither one of them fires the spark plugs.

So if the Signal Generator (Trigger) is good, the Igniter box is good (newish) and it's probably not the Coils, what else can it be? By the way, the battery is shot, so I crank the bike over by way of hooking it up to a non-running car battery.

One last thing...all electrical works! Everything but the horn. Not sure if that bit of information helps...Any more ideas???