Trying to isolate whats burning ignitor/coil

Go back to a point set. A EI conversion IS NOT a upgrade!!

Yes on Autolite 24 @.035.

Coil should not be hotter than the exhaust manifolds. If it is, you need a ballast resistor (look under the breaker cover at rear of the engine, you may already have one that was disconnected).

I think you can put some dielectric grease in the wire boot to prevent arcing, you may want to try that before replacing the wires.

wwchevy wrote: Hollywood wrote: This seems to be the most logical instruction sheet for an EI conversion I've seen. "Using a coil with too little primary resistance can cause the ignition module to overheat and misfire until it cools down again or fail, voiding the warranty." I actually have the Hot Spark EI conversion on my last 3 boats with no problems. HW is correct about the instructions. Start at the top and go step by step with the digiatl multi-meter. That will tell you weather you need a ballast resistor in the system or not. Someone had put an Accel coil on my current boat and I switched back to the stock coil because the Primary resistance was too low on the aftermarket coil- about 1.0ohms instead of the minimum of 1.5ohms. I run the ballast resistor because my coil states that it requires an external resistor and when I checked the voltage as stated it was within spec with the external resistor in place. Go back to the basics and good luck.

+1 YES, YES, YES. Good find on those instructions. Fix your plug gap then follow the steps!

Hollywood wrote: This seems to be the most logical instruction sheet for an EI conversion I've seen.

"Using a coil with too little primary resistance can cause the ignition module to overheat and misfire until it cools down again or fail, voiding the warranty."


I actually have the Hot Spark EI conversion on my last 3 boats with no problems. HW is correct about the instructions. Start at the top and go step by step with the digiatl multi-meter. That will tell you weather you need a ballast resistor in the system or not. Someone had put an Accel coil on my current boat and I switched back to the stock coil because the Primary resistance was too low on the aftermarket coil- about 1.0ohms instead of the minimum of 1.5ohms. I run the ballast resistor because my coil states that it requires an external resistor and when I checked the voltage as stated it was within spec with the external resistor in place. Go back to the basics and good luck.

I changed the plugs, plug wires, and distributor cap. From talking to others old plug wires could be/been the cause. Previous cap and plugs all seemed fine but changed them anyway.
I used autolite 24's gap .50ish not sure of the old plug gap.

That is a great write up, saved right to my favorites!

Spark plug wires were pretty old, maybe they were causing the coil to over-heat.

After replacing spark plug wires, plugs, and new distributor cap all seems well so far. I ran her for about and hour out in the open water then ran her at idle for about two hours at the dock without the coil over heating. Yesterday, it had over heated by now.

I bought but did not install resistor, wanted to do things one at a time in order to know what's causing/caused the problem or it would bother me not knowing.

Thanks you guys for your input, will update if it fails again, otherwise I'm a happy skier!

Plan B wrote: It seems to have everyone stumped that I have talked to. I hope my last few hail mary's pay-off tomorrow.

Well I hope you believe in miracles.

Plan B wrote: she started right up. Happy to see that the pertronix is atleast going into protection mode like it claims. Now hoping that tune-up will be the fix for the coil overheating.

Throw away the Pertonix crap or put a ballast resistor or wire in before feeding the + side of the coil.

I've been having the same issue with my 79 commander which has a petronix ei upgrade in the points type dist. It's wired correct and I've tried with & w/o ballast resistor as well as internal and external coils. Just pulled distributor and having it rebuilt with points installed. After being stranded many times and spending a small fortune on coils, I plan to keep spare points and condenser on board for a quick change if ever needed.

I don't know, if Pertronix says you don't need the resistor...the arithmeticsays you are putting aa lot of amps through that circuit. The evidence says your coil was really hot and now you have no spark. Your local auto parts store should have a ceramic ballast resistor in stock. You won't hurt anything by adding the resistor, what you are doing now is not working.

Petronix guy says I do not need a resistor...

He had me run a test, run a ground wire from block to negative on coil. He wanted voltage at coil while engine turning and with on position.

with on position I was reading 11.5v

While turning I was reading 9.2v

Gary, I trust your judgement and at this point would be more than happy to give your recommendation a shot. Is this something I can pick up locally, if so what specifically am I looking for? Seems like another new coil may be on the list also.

What do the installation instructions say about circuit resistance?

With the key on, set your volt meter to DC volts in the 20 volt range and touch the positive lead to the positive side of the coil, and the negative lead to the engine block, what is the voltage?

Ok, re-wired all my accessories to run independently straight from the battery (fuse box) vs. there original position from the ignition switch.

FYI, I initially daisy chained accessories to ignition thinking this would prevent unwanted battery drainage...lesson learned.

Installed new pertronix II ignitor and coil (0.6 ohm). Not super savvy with multimeter so I'll explain in detail what I did and what I got.

With no key in ignition..

Primary test - Set to Ohms, (-) lead to (-) post on coil, (+) lead to (+) post on coil, meter was jumping from 000.4 to 000.6

Secondary test - Set to Ohms, (-) lead to center of coil, (+) lead to (+) of coil, meter read 9

I'm hoping this is the fix to what was causing my coil/ignitor to burn up. If it is great, although, I still find it bothersome knowing that if the key is accidentally left in the "on" position how easily it is to burn up the system. There must be a way to eliminate this. The pertronix II does state, "Senses startup and develops more energy for quicker, easier starting. Built in reverse polarity and over current protection shuts down the system, preventing component damage." I hope this will also help in my situation vs. the pertronix I system which did not do this.

Boat starts and runs beautifully! Hopefully for more than 3 hours this time!!!

I just replaced the ignitions switch, if I would have known this prior, I would have opted for one with an ACC option.

My nav light switch has been re-wired to the 6-gang rocker switch board   

Thanks for the knowledge fella's, hoping to receive new ignitor/coil within the next few hours...of course the water is like glass...

You could always replace the ignition switch with one that has an ACC position and wire the radio to that (just like your car). Just put it on ACC when the engine isn't running and you want to listen to the stereo.