How Hot is toHhot ?

I just installed new dyna s and 3ohm coils on my 1975 Z1 also did the coil mod.
After less than 3 mins with ignition on but bike not running both the coils were HOT almost to hot to touch.
I know coils get hot but how Hot is to HOT.

Jimstan

That is one of my concerns with the Dyna S ignitions. The coils are on all the time when the bike is not running. The same thing can happen to one or both coils with a stock points system, but not on a stock KZ electronic ignition. I think this is the cause of many of the Dyna S failures (not that they have a lot of failures, but of the ones that do fail, I think this is a major cause).

Coils get pretty hot during normal use (much hotter with the Dyna ignition than with the stock points or elec. ignition). Newer coils seem to handle the abuse better than the old ones. It shouldn't get too hot to touch briefly.

If already have the coil-mod, it wouldn't be too hard to make a holding circuit where the coils don't get power til you hit the starter button. Then they would stay on until you hit the kill or ignition switch. It would take another relay, or just some re-wiring of the kill/start switch.

Post edited by: loudhvx, at: 2007/07/24 14:40

loudhvx wrote:

That is one of my concerns with the Dyna S ignitions. The coils are on all the time when the bike is not running. The same thing can happen to one or both coils with a stock points system, but not on a stock KZ electronic ignition. I think this is the cause of many of the Dyna S failures (not that they have a lot of failures, but of the ones that do fail, I think this is a major cause).

Coils get pretty hot during normal use (much hotter with the Dyna ignition than with the stock points or elec. ignition). Newer coils seem to handle the abuse better than the old ones. It shouldn't get too hot to touch briefly.

If already have the coil-mod, it wouldn't be too hard to make a holding circuit where the coils don't get power til you hit the starter button. Then they would stay on until you hit the kill or ignition switch. It would take another relay, or just some re-wiring of the kill/start switch.<br><br>Post edited by: loudhvx, at: 2007/07/24 14:40

Hey in my Dyna-S literature, in the troubleshooting section it goes through some different steps, but one part cautioned to not leave the coils powered for more than 5 minutes without the bike running or they can overheat and fail. The way I wired my bike, the relay powering the coils is energized by the kill switch so the coils are only powered just as I begin the startup procedure and flick the kill switch to run.