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littlemarv

External coil on a 23D

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littlemarv
Awhile back, I posted about a questionable coil on my 23D. It wouldn't fire, the points and condenser were rotten. I dropped 20 bucks on a mega fire II ignition module. Put it on, engine popped once or twice, then nothing. Now I dropped 30 bucks on points and condenser, installed and set gap to .020". Now absolutely no spark. Could I have wrecked the coil by putting the mega fire on it? The points close on top of the compression stroke for a split second and are open through the rest of the rotation. I assume this is correct? Under the points cover, I have three wires going to the isolated screw-one from coil, one from condenser, and one that goes out to the engine kill swich. I searched around the archives a bit about external coils. To install an external coil, do I just put 12V switched power to one side and hook my points and condenser to the other side? Do I need a certain coil, or can I go to Napa and tell them to give me any old coil? I'm just trying to get this tractor running to test it. Any help is appreciated, ignition is a mystery to me...

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RayS
The mega fire would not harm the engine or ruin a magneto. They were designed to replace points. They have no power going to them. Try this if you want to switch to external coil. http://www.simpletractors.com/do_it/magneto_to_coil.htm

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midnightpumpkin
E-Bay is an excellent place to find a suitable coil. Just type KOHLER COIL in the search field. A coil for a single cylinder Kohler is what you want to use. It does not require an external resistor. Most automotive coils need an external resistor. You need one that looks like this [url]http://www.ebay.com/itm/NOS-Ignition-Coil-John-Deere-140-Garden-Tractor-Kohler-K321AS-Engines-LB-81-12v-/180808302142?pt=LH_DefaultDomain_0&hash=item2a1903be3e#ht_1301wt_1029[/url] BTW not a bad price for a new one shipping included. JOhn U

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henroan
I just used an old coil that a neighbor had in his garage. Any 12v should work. You have the set-up right when you get the coil. I converted both of mine and not had any problems since. Good luck.

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gwiseman
I have a NovaII electronic clicker on a fdt 10hp briggs 24343. Had to re-learn how to start the engine after toasting 2 coils. This engine fires after releasing the starter button, not while depressing it. Therefore I found that turning the key to the on position, next depressing the starter button spinning the engine 3-5 times, then releasing the starter button the engine will usually hit. Normally it will start on the 1st or 2nd repetition of that starting proceedure. Still not normal for me to allow the starter button to depress to start the engine but after replacing 2 coils I have learned to be patient. BTW I plan to install another NovaII or like electronic module on my 3112h in the future as the points are starting to show wear.

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Willy
Before installing a external coil I would try unhooking the kill wire and see if that might be shorted out. If you hit your local auto salvage and get a older Chevy coil, they have a built in balast resister and are a lot cheaper than a new one.

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GrincheyOne
I agree with John U, about the ebay offer. A new dura-last at Auto-Zone will ren about $30. MIght do better at a local auto salvage yard. It was a simple task to rewire, basically abandoning the entire magneto system. Only the points are used to switch the negative (ground) side of the automotive coil. Works great on a cold day (or nite). Solved my starting problems with the '68 Landlord.^ Wayne

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littlemarv
Problem solved...... Got a coil, condenser, and wire. Installed all three. Still no spark. I was just using jumper wires to temporarily hook up for now, noticed that when I unhooked the wire going to the terminal on the points the spark plug would fire. So the points arent doing their job. Put my meter on the points, noticed that when the points were closed the resistance to ground would go down by .1 ohm. Discovered that when I changed the points, there is a bracket under them with two prongs on it to hold the boot on the plunger. That was out of place and shorting the points! (Lots of colorful language omitted here). Installed bracket correctly and hooked up the old magneto and condenser and engine fired right up. Lesson learned. I now have an external coil setup in stock in case I ever need one. Rather an expensive lesson, but if you had a questionable COIL its handy to have because I don't think you can really test a coil with a meter. Thanks for all your help everyone, ignition is no longer a mystery to me.....

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JimDk
Congrats on successfully solving your ignition problem. Magneto ignitions are one of the most mis-understood problems that members, new to these old tractors, have. You used a tool that should be mandatory in all our tool kits. That is the VOM meter. The ohm meter is invaluable for checking points and circuits. Good job.

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DaveTenney
gwiseman, That's a pretty weird problem...I have the Nova II on a few motors. The Nova II is not wired to the battery at all so what ever you are doing with the start button would have no bearing on any part of the ignition system. Those ignition modules replace the points...I'm thinking you either have something wired wrong, or a case of bad luck! Dave

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gwiseman
quote:
Originally posted by DaveTenney
gwiseman, That's a pretty weird problem...I have the Nova II on a few motors. The Nova II is not wired to the battery at all so what ever you are doing with the start button would have no bearing on any part of the ignition system. Those ignition modules replace the points...I'm thinking you either have something wired wrong, or a case of bad luck! Dave
I think weird may be correct. Bought the tractor several yrs ago & it was really worn at every working joint (like it had been a working in sand). Rebuilt nearly everything except the motor that had previous "overhaul" by PO including electronic ignition. I've torn into it and traced wiring twice but can't find an obvious problem. She's a great worker with a quirk & a valued member of the fleet anyway. Thx

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