coils dead

[sullivan.dave]

I am one of those lurkers that have managed to get addicted to an old 1982 gs1100L, with the help of the assembled multitude on this forum. I am the third owner of this bike with app. 26000 miles on the odometer and I have had a tough year. I have rebuilt most of the electrical system with the help of a good mechanic and the stator papers.
I am currently having trouble with coils failing at an alarming rate. Last pair quit functioning with less that 100 miles on them and more than walking distance from home. I have tried to mine the various threads, but am confused about the electronic ignition/igniter relationship to the entire ignition system. With new coils, cycle fires up and runs like a deer. A hundred miles later it starts missing and would not cover 30 miles before both coils quit firing.
Less than 400 miles on new stator, r/r, battery and used igniter, and total of 5 coils from donor bike and ebay.
I intend to order new coils, but would like to know what to look for, in order to prevent another burnout at some distance from home. I would post current electric info, but since I am out of coils, can't even start with charging system info. It was working within specs prior to last coils install.
Any suggestions about where to go or what to do next, would be appreciated.

[mortation]

Are you replacing the coils with new or used coils?

[sullivan.dave]

both

1st replacement was new for cyl 2 and 3, then two used ones from donor gs1100, and 2 from 89 katana (these were the only pair I put in at the same time.)
Dave

[Guest]

While running at 5000 rpms what is your readings off the battery with a multimeter? Sounds like the R/R isn't regulating.

Have you checked the igniter if the R/R isn't the issue?

[sullivan.dave]

13.4 to 13.8 so the R/r is doing it's job. How do you check the igniter?

[salty_monk]

It's fully written up in Clymers or Haynes. My manual isn't to hand now. Do you have one?

You're basically testing to make sure it is putting out a signal. I can't see how it would kill your coils though, if the bike runs ok then it should be fine (unless it's putting out double the signals or something I guess....)

What about the input voltage to the coils? Is that correct? What plugs are you using? I don't really see how you can overwork the coils. You might be able to overheat them i guess... that could make the insulation break down inside. Get some Dyna greens new... at least if you blow them they will be under warranty.

I would replace both of them together. Presumably it's a wasted spark system with 2 coils on 4 cylinders?

Cheers,

Dan

[sullivan.dave]

Thanks for the advice, because of the intermittent nature of the problem, I have more than average difficulty running tests. Guess that is what winter is for.

[Thomas Kenny]

Check your current at the coils and make sure you have a solid 12 volts going to each coil. My wiring harness on my 1985 GS550ES began to break down and I was getting intermittant good voltage and then down to 10 or 11 volts and the bike would not run. I wired a relay from the battery direct to the coils using a thread search on this forum.

I now have direct voltage from the battery to both coils which are new Dynas but still had the problem with the new dynas until I installed a relay. Won't cost you much to give it a try if you are down on voltage at your coils. Good luck :-D

[sullivan.dave]

End of story

Thanks for the replies. I checked the things that you all kindly mentioned , and was about to the point of trying a new wiring harness. Checking continuity on the problem wasn't resolving the problem, until I tried it inplace after it (coil for cyl. 2 and 3 ) gave out yet again.
The positive lead did not show continuous connection. The l shaped lead to the coil had a crack in the brass and it was covered and supported by the plastic insulation. It would vibrate apart after 30 to 100 miles on the road and as soon as I pulled the leads from the coil it reestablished the connection.
Hope this helps someone else.