12 V coil Conversion-hot coil?

[KenW]

I converted my Simplicity 725 with a 7.25 hp Briggs model 19 to a 12 coil system. I mounted the coil to the top horizontal hood support so it is close to the top of the engine. After running it a bit it gets very hot due to its location. It is about as hot as the fins on the head. Is that amount of heat an issue? Thanks...Ken Williams

[carter]

Mine's in the same location. I've never checked it after a long run but I've never had a problem with it. They get plenty hot under the hood of a vehicle. Ron

[ka9bxg]

Do you have a resister block in line I know on big tractors that you need it or you will burn up the coil.I put a coil on my 19d and ran good for about 10 minutes then it quit I will try agian with a Dodge resister block.

[SmilinSam]

I was always under the impression that the resistor in the line was if you were using a 6 Volt coil in a 12 volt system. that is what the situation was on my previous WD tractor. On my WD45 I just used a 12 volt coil and eliminated the resistor to the coil. I have 12 volt coils on several old briggs engines and they have been running fine. Sam

[MPH]

new Idea to me, whats the gain in putting 12v coil on these small engines??????MPH

[SmilinSam]

When the mag goes bad on a Briggs it is easier to change it over to a external battery ignition setup like Kohler uses than to take the Briggs out of the tractor and fix it. I find that they start better with Battery Ignition than with the standard Briggs ignition.(the exception being the Briggs magnetron electronic ignition)

[Roy]

I think the resistor is to drop the voltage to the points and thereby increase the life of the points. Most cars with resistors (internal or external) have a bypass circuit to put full battery voltage on the coil while starting. My 2 cents worth. Roy

[KenW]

The coil has an internal resistor (required for the conversion) Another advantage is it starts easier in the winter. Some car coils have the internal resistor and some do not. I used a Kohler coil and a Kohler 12v condenser as well as a Kohler high tension lead.

[dvogt]

if you have a coil with 3-5 ohms of primary resistance a inline resistor is not needed , if you are using a typical chevy coil they have only 1 -1.5 ohms of primary resistance you will need a external resister . if you are unsure of what you have take a ohm meter & measure the resistance across the + & - terminals on the coil with the wires disconected .