New build, Dyna coils getting hot...

I have just finished the wiring harness reinstal on my 1980 kz650. I made the minor changes to add a dyna S pickup and Dyna coils. I had the key on for a few minutes wile I was figuring out the turn siganl wiring connections and noticed that the coils were getting warm, almost hot. So I disconnected the power to them. I am very certian a have them connected correctly. IS this normal with the key on and the engine not running? Or do I have an obvious mistake here?

What is the resistance of the coils? Did you replace those as well or did you keep the stock ones?

Tyler wrote:

I have just finished the wiring harness reinstal on my 1980 kz650. I made the minor changes to add a dyna S pickup and Dyna coils. I had the key on for a few minutes wile I was figuring out the turn siganl wiring connections and noticed that the coils were getting warm, almost hot. So I disconnected the power to them. I am very certian a have them connected correctly. IS this normal with the key on and the engine not running?

Yes, that is normal with the Dyna S, but hard on the coils and Dyna S module. Depending on how it's wired, you can prevent that by killing the power to the coils by turning the kill switch to off. Then you can turn on the ignition switch to work on lighting.

Great! thats what I hoped was the case. They are the 3 ohm dyna coils and are new. I have never worked with this system before and didn't want to break all those shiny new parts. For saftey sake I will get in the habbit of leaving the kill switch off. I have it wired to the factory wire for "key-on" ignition power.

Thanks

Tyler wrote:

Great! thats what I hoped was the case. They are the 3 ohm dyna coils and are new. I have never worked with this system before and didn't want to break all those shiny new parts. For saftey sake I will get in the habbit of leaving the kill switch off. I have it wired to the factory wire for "key-on" ignition power.

Thanks

Good way to do it and have 2 ways to kill the engine.

loudhvx wrote:

Tyler wrote:

I have just finished the wiring harness reinstal on my 1980 kz650. I made the minor changes to add a dyna S pickup and Dyna coils. I had the key on for a few minutes wile I was figuring out the turn siganl wiring connections and noticed that the coils were getting warm, almost hot. So I disconnected the power to them. I am very certian a have them connected correctly. IS this normal with the key on and the engine not running?

Yes, that is normal with the Dyna S, but hard on the coils and Dyna S module. Depending on how it's wired, you can prevent that by killing the power to the coils by turning the kill switch to off. Then you can turn on the ignition switch to work on lighting.

Sounds like a dumb circuit design if they leave the coil drivers turned on indefinitely. In an electronic ignition design it would be really easy to use some kind of a timed trigger to turn the drive on the gate for the FET which draws the current through the coil primary a specific time period then shut off until the next trigger pulse is received. A design that leaves those FETs on to cook is just plain dumb.

bountyhunter wrote:

loudhvx wrote:

Tyler wrote:

I have just finished the wiring harness reinstal on my 1980 kz650. I made the minor changes to add a dyna S pickup and Dyna coils. I had the key on for a few minutes wile I was figuring out the turn siganl wiring connections and noticed that the coils were getting warm, almost hot. So I disconnected the power to them. I am very certian a have them connected correctly. IS this normal with the key on and the engine not running?

Yes, that is normal with the Dyna S, but hard on the coils and Dyna S module. Depending on how it's wired, you can prevent that by killing the power to the coils by turning the kill switch to off. Then you can turn on the ignition switch to work on lighting.

Sounds like a dumb circuit design if they leave the coil drivers turned on indefinitely. In an electronic ignition design it would be really easy to use some kind of a timed trigger to turn the drive on the gate for the FET which draws the current through the coil primary a specific time period then shut off until the next trigger pulse is received. A design that leaves those FETs on to cook is just plain dumb.

that pretty much sums up the stock wiring on most vehicles,2 or 4 wheeled! :laugh:

bountyhunter wrote:

Sounds like a dumb circuit design if they leave the coil drivers turned on indefinitely. In an electronic ignition design it would be really easy to use some kind of a timed trigger to turn the drive on the gate for the FET which draws the current through the coil primary a specific time period then shut off until the next trigger pulse is received. A design that leaves those FETs on to cook is just plain dumb.

Yeah thats exactly right. I guess this explains the posts I have read here and on other sites where people have reported burning up the dyna ignition. As long as you know you have top be careful then it is not that big of a deal. Still a bad design non the less.

It's the same design with most of the electronic ignitions out there. The same thing happens with points too.

The only one that doesn't do that (as far as I know) is the factory Kawasaki ignition.

... and of course the HEI mod version, the Loudhvx version, and the HEI mod version for points.

loudhvx wrote:

It's the same design with most of the electronic ignitions out there. The same thing happens with points too.

The only one that doesn't do that (as far as I know) is the factory Kawasaki ignition.

Probably a really good recommendation for the type of CD ignition I have on mine. No DC current at all in the coil, just pulses and you only get a pulse for each opening of the points. Coil doesn't do anything at all sitting with the key on.

bountyhunter wrote:

loudhvx wrote:

It's the same design with most of the electronic ignitions out there. The same thing happens with points too.

The only one that doesn't do that (as far as I know) is the factory Kawasaki ignition.

Probably a really good recommendation for the type of CD ignition I have on mine. No DC current at all in the coil, just pulses and you only get a pulse for each opening of the points. Coil doesn't do anything at all sitting with the key on.

Yes, but we still don't know what you have, do we?

loudhvx wrote:

bountyhunter wrote:

loudhvx wrote:

It's the same design with most of the electronic ignitions out there. The same thing happens with points too.

The only one that doesn't do that (as far as I know) is the factory Kawasaki ignition.

Probably a really good recommendation for the type of CD ignition I have on mine. No DC current at all in the coil, just pulses and you only get a pulse for each opening of the points. Coil doesn't do anything at all sitting with the key on.

Yes, but we still don't know what you have, do we?

It's an aftermarket CD ignition built from a kit. It was sold back in 1982, and called a "Tiger CD" or something to that effect. But, all CD ignition work on the same principle: a free running DC-DC converter boosts the 12V up to 400V, and that charges a 2uF/600V polypropolene storage cap. An SCR knoks the 400V supply down when it fires and that dumps the cap's voltage across the primary of the coil. No DC current into the coil is possible because the coil primary is capacitor coupled.