Coil is getting hot 3.0 Mercruiser

badboatguy

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Joined
Oct 23, 2020
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4
I have a 1989 3.0 mercruiser where I installed a Ignitor 1146A, and Pertronix 3ohm Flamethrower coil. I installed by eliminating the resister wire and instead ran a hot line from the choke. Right now the boat starts great and will run perfect for an hour or two and then cut out and die. It will restart after cooling off for 1/2 hour or so. I had originally installed it using the factory resister wire and recently changed it as described above with no improvement. When it cuts out the coil and distributer are too hot to touch. I'd greatly appreciate any advice, thanks!
 
Joined
Mar 27, 2010
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3,008
I think you were not suppose to remove the resistance wire. Ballast resistor and resistance wire are the same thing.... If you read the instructions, it says if your ignition system presently is equipped with a resistor/wire, do not remove it. https://cdn.shopify.com/s/files/1/0247/6913/4628/files/1146A.pdf

It looks to me according to that link that the red wire to the Ignitor goes to full 12 volts. The (+) terminal on the coil gets voltage thru the resistance wire still.
 

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badboatguy

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Oct 23, 2020
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I just called the help line you posted in the instructions and he said that supplying the full 12 volts for the coil and ignitor is fine with the 3ohm flamethrower coil that I have since the coil has an internal resistor. He suggested that the problem might be poor grounding through the ignitor base plate, distributer, and distributer hold down bolt. He suggested I check the resistance between the neg wire on the coil and the base plate and that it should be less than .02 ohm. I'll check that and clean everything up and see what happens. Thanks for posting the link, much appreciated!
 

Direwolf269

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Joined
Jun 8, 2021
Messages
8
I'm having a similar problem with my setup on a 470 except that my coil actually burns out (X 2 ! 1.5 ohm coil with resistor in place and 3 ohm without). Did you make any progress?
I talked to Pertronix tech support (again) and all they could come up with was voltage spike from the alt., which was just tested.
Make sure to check your high tension wires and plugs, too much resistance will cause coil to overheat
 

Benny67

Chief Petty Officer
Joined
Apr 21, 2015
Messages
571
I have a 1989 3.0 mercruiser where I installed a Ignitor 1146A, and Pertronix 3ohm Flamethrower coil. I installed by eliminating the resister wire and instead ran a hot line from the choke. Right now the boat starts great and will run perfect for an hour or two and then cut out and die. It will restart after cooling off for 1/2 hour or so. I had originally installed it using the factory resister wire and recently changed it as described above with no improvement. When it cuts out the coil and distributer are too hot to touch. I'd greatly appreciate any advice, thanks!
I'd suspect the pertronix module would be failing. The coil is just a winding of wire. It's going to either work or not.
The fact it's getting hot would lead me to believe it's drawing more current than it should. Meaning the module is probably causing the issue.
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,291
burned up/arcked points and timing issues

there caused by overvoltage and bad condensors, the timing change is .001 of an inch equals 1 degree of timing. smaller gap, increased timing, larger gap ,decreased timing. But no matter how bad they got they would always produce some level of spark.
Electronics are fine, just there a on-off switch works or it dosent
 

Searay205

Chief Petty Officer
Joined
May 27, 2018
Messages
468
Used points and condesor from 1998 to 2018 never had an issue. mercruiser 3.0 liter. thousands of hours, oh and original spark plug wires also except coil wire I had to replace it once....
 

Direwolf269

Cadet
Joined
Jun 8, 2021
Messages
8
there caused by overvoltage and bad condensors, the timing change is .001 of an inch equals 1 degree of timing. smaller gap, increased timing, larger gap ,decreased timing. But no matter how bad they got they would always produce some level of spark.
Electronics are fine, just there a on-off switch works or it dosent
not to mention my kids have this terrible habit of shutting down with lanyard switch and not the key.
BBguy, did you make any progress with your trouble?
 
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