682 Coil

Finster · #1 02-01-2011, 10:25 PM

I have a 682 with a kt17 and it looks like the ignition coil pooped out on me. Last I replaced it a few years back, I got it from my local dealer for 115$ and he had to order it. We just had 8" of snow dumped on us and more on the way, I need to get this thing back up asap. Is there an alternative coil I can use that will work on this engine? Something more common that my dealer would have on hand or even something for an automotive application?

R Bedell · #2 02-02-2011, 07:08 AM

The KT-17 has a "dual" ignition coil. I have not seen any aftermarket replacements being offered.

Matt G. · #3 02-02-2011, 08:00 AM

Here's one.

young enthusiest · #4 02-03-2011, 11:16 PM

I own a few of those. Kirk engines is the best. Fast shipping even to Canada. Great prices too. That coil is great. I have one on my 784

Finster · #5 02-05-2011, 04:19 PM

Just thought id post a follow up reply to share what ive learned. Ive got the tractor running, and the snow moved. So thanks to everyone that replied.

Let me start by saying that I'm a millright by trade and I am accustomed to using unconventional wisdom and I'm not afraid to stray off the beaten path if it means getting the job done.

So far ive learned that my local dealer now wants 187$ for the same coil (WOW!) and would still take 5+ days to get. I learned that I can get the same coil off of ebay for 97$+12 shipping in the same amount of time. Ive also learned that O'Rielly's auto parts can get the coil. You have to look up the part # in book 7 of their small engines parts book for 106$ and no shipping. The best value overall. None of these options seemed very appealing as they'd leave me a mountain of snow to move with a shovel. So I decided to try something else.

The first two pics were my first attempt:

I used (2)motorcraft coils I had laying around in the garage from an old project car, and a couple of accell plug wires off the same mustang. Made a small bracket with some scrap metal to mount them. They are wired in series, pos to pos, neg to neg....ect. As the tractor only has 1 set of breaker points, wired in this manner both coils would fire at the same time just as the oem coil. I also installed a ballast resistor (the white block on the firewall) as these coils do not have an internal resistor and was not sure if the tractor had a resistor wire or something similar already. With the extra ballast resistor the tractor would not fire. After removing the ballast resistor the tractor finally started (easier than it ever has i might add...1/2 turn cold) and it ran at idle but as soon as I gassed it, it just kind of laughed at me. Backfire from both the exhaust and the intake. Running very rich. No amount of adjustment in the points would make it run decent. Now this idea isn't without merit. I think it would work, with some minor mods. I believe my main problems were:

*Using Solid State coil for an electronic ignition system on
a breaker point system. The SS coils have a higher
resistance than points type coil. So swaping out for an
older motorcraft, GM, ect. coil from a points system.
*Signal degradation due to the excessive length of the
plug wires, as I was not willing to cut them down.

I believe with these two problems resolved it would work, and may even be a cheaper alternative as you can replace one coil at a time as they go bad for about 15-20 bucks a piece.

The second two are my second and more successful attempt:

I went down to my local Harley Davidson shop and talked to one of the old timers at the parts counter. Explained to him what I was looking for and immediately a light bulb went off. "That looks like a coil off an old shovel head". He went in the back and brought this coil out to me. Part #31609-65A. With this coil the tractor started right up and runs smooth. I still have a couple of timing issues to resolve but the coil seems to be a direct replacement of the oem. Just needs a simple angle iron mount with a couple of holes drilled in it.....and the best part? $51.94. I can go through 3 of these for the price of 1 oem from my local cub dealer, and no wait on shipping as the Harley shop stocks these. This may end up being a permanent replacement.
Now, one more question. Do the oem coils have an internal resistor or is there one already on the tractor? I checked the voltage at the new coil and its around 7-8 volts, which seems to be about right. I just want to make sure I have the wiring right and dont burn this new one up right away.