Converting a Kohler K321 from breakerless Ignition to Points

MNGB

MNGB

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The 1973 Power King has a Kohler K321S engine it came from the factory with the Kohler Breakerless ignition system (electronic magneto) for reasons unknown to me they only produce the system for less thaen 10 years then went back to points until they came out with the Magnum series engines. When Kohler ceased production of the system they also pretty much stopped making parts so new coils, triggers are NLA, back in the late 70's and 80's they offered a Kit to convert to battery ignition but those kits are far and few now days, but finding the parts needed is easy to do. Anyway this fall my Grandson was helping me put the tractors away for winter and the ones I wanted in the shop moved to the shop, well the 73 PK would not start we finally figured out it had no spark the Breakerless system had failed and they do that with no warning. So the thing to do is convert the engine to battery ignition I have all the parts in the parts room so it was just a matter of getting at the project. So after getting the Kubota finished up and ready for winter the 73 Power King getting my attention
 
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I made the conversion once. If I remember rightly, I removed the plug and added the push rod(use the steel one, not the aluminum). You must remove the coil and replace with a conventional one. Add the plate and points and cover. Also, you must change the ignition switch. There is also the choice of using and after market breakerless system.
 
Was into the shop this morning and got a few things done on the PK, got the new coil secured with 2 screws had to elongate the holes in the mounting bracket attached the wire clamp for the points to the engine. First pictures are of the breakerless ignition parts that are removed, that's the coil and the trigger then is a list of the parts needed for the conversion and pictures of the engine etc. The good thing is when Kohler went to the Breakerless system they didn't change the cam so the points plunger lobe was still there and on the blocked they still machine the points mounting area drilled and tapped the 4 10-24 holes for the points and points cover.I had to remove the plug in the block for the points push rod for many years they installed a tight fit plug in the hole that had to be punched into the engine on this engine they had a plig with a rim on it like a 22 cal rim fire bullet. I tried to pull or pry it out but couldn't get a good grip on it so I center punched it and drilled with a #40 drill then went up to a #39 then ran a SS sheet metal screw in the hole and using my small slide hammer to get it out and that worked good, oiled the points plunger rod and installed and ran qa 10-24 tap in the mounting holes

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MNGB said:
The 1973 Power King has a Kohler K321S engine it came from the factory with the Kohler Breakerless ignition system (electronic magneto) for reasons unknown to me they only produce the system for less thaen 10 years then went back to points until they came out with the Magnum series engines. When Kohler ceased production of the system they also pretty much stopped making parts so new coils, triggers are NLA, back in the late 70's and 80's they offered a Kit to convert to battery ignition but those kits are far and few now days, but finding the parts needed is easy to do. Anyway this fall my Grandson was helping me put the tractors away for winter and the ones I wanted in the shop moved to the shop, well the 73 PK would not start we finally figured out it had no spark the Breakerless system had failed and they do that with no warning. So the thing to do is convert the engine to battery ignition I have all the parts in the parts room so it was just a matter of getting at the project. So after getting the Kubota finished up and ready for winter the 73 Power King getting my attention
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Perfect timing and doing this swap, GB. Dad picked up a K321 from a Cub Cadet 1450 that one of his buddies had laying around in his shop and he wants to try to get the economy running. He was wondering why the CC engine had points setup and the Economy didn't. This gives us the procedure on making the swap to the points system and we should have most if not all of the parts on hand.
 
Propane1 said:
I never heard or seen that set up before Gary. Interesting. Where was the trigger pickup mounted. It would have a different flywheel too, ? And there would be no timing adjustment. ?

Noel
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Correct on the timing the stator had a post and winding to power the system not positive but pretty sure the flywheels are the same the trigger is mounted on the engine bearing plate on the RH side at about the 9:30 position
 
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MNGB said:
Correct on the timing the stator had a post and winding to power the system not positive but pretty sure the flywheels are the same the trigger is mounted on the engine bearing plate on the RH side at about the 9:30 position
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Not trying to disagree with you Gary but I think you will find the trigger portion for the electronic ignition system is part of the small two terminal module that you removed - it has a small voltage coil that triggers (turns on) the SCR on to allow current to flow from the capacitor to the ignition coil by providing a ground path for the high voltage charge stored in the capacitor that is connected to the ignition coil. The charging coil that is part of the stator is designed to provide a high voltage (about 150 - 300 volts) current to charge the capacitor through a diode.
Attached is the Kohler information on the system (shows the schematic) as well as the sheet that was shipped with the conversion kit. The circuit system is very similar to the circuit that Wisconsin used for the electronic ignition system on the TRA12D. For anyone interested I can provide the schematic for that system as I took a bad module apart a few years ago, identified the components and created a new working module that could be connected to the charge, trigger and ignition coils (if they were still ok) and allow the electronic ignition to work again. My guess would be that the SCR inside the trigger module failed resulting in the no spark condition you encountered.
 

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29 Chev said:
Not trying to disagree with you Gary but I think you will find the trigger portion for the electronic ignition system is part of the small two terminal module that you removed - it has a small voltage coil that triggers (turns on) the SCR on to allow current to flow from the capacitor to the ignition coil by providing a ground path for the high voltage charge stored in the capacitor that is connected to the ignition coil. The charging coil that is part of the stator is designed to provide a high voltage (about 150 - 300 volts) current to charge the capacitor through a diode.
Attached is the Kohler information on the system (shows the schematic) as well as the sheet that was shipped with the conversion kit. The circuit system is very similar to the circuit that Wisconsin used for the electronic ignition system on the TRA12D. For anyone interested I can provide the schematic for that system as I took a bad module apart a few years ago, identified the components and created a new working module that could be connected to the charge, trigger and ignition coils (if they were still ok) and allow the electronic ignition to work again. My guess would be that the SCR inside the trigger module failed resulting in the no spark condition you encountered.
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Thanks for the great information Stew of course you understand all the good stuff me not so much not worried about any disagreement as I said I know little about the system, oh by the way I did not remove the trigger on the engine as it involves to much work when its installed in a PK and leaving it in place hurts nothing
 
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Well no progress made on the points conversion, first my shop furnace took retirement luck for me my brother had one he didn't need so we got that installed and heat was good. Came into the shop Monday morning went into the office no heat, figured the pilot light just went out firedit up was taking my jacket of heard a click and the heater was off fired it up again and it ran about 2 minutes heard the click again no flame, its 25/30 years old so figures I get a new wall heater went to Menards and picked one up, paid the lady cash and went on my way got home and realized I didn't grab my receipt. Got busy and installed the new heater fired it up was enjoying heat when the darn thing went out fired it up 2/3 more times and it will not stay burning more than 3-4 minutes, reread the manual did all the things it said to do no joy. So I called Menards talked to a nice Gal at the front office told her my sad tale about not grabbing my receipt she said not a big problem if I just wanted to exchange it for another one like it and I said I did so this afternoon will go in and see how this goes
 
This magazine article may be of interest to someone who wants to better understand the CDI ignition system used on most first generation small engine electronic ignitions. It also details a replacement module that can be constructed with new electronic parts if the charge coil, trigger coil and ignition coil wiring is still ok and can be easily accessed.
 

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cjet69 said:
Sounds like your infested with heat gremlins. ;) Nice to hear they will exchange the new heater for you.
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What a deal exchanging the wall heater turned into, got it packed up and went to the store exchange lady said no problem left the bad on here and go get one off the shelf off I went picked up a heater went back to the return area new lady but she said took her scanner deal and scanned the code on the box but the printer would not print the tag she messed with some called another gal, she looked it over removed the paper roll replaced t nothing banged it a couple of times nothing looked under the counter a bunch of papers and misc flew out still nothing. She was about to give up when she checked the power supply and Discovered it was unplugged plugged it in and it was working, I'm off for home got to the shop opened the box and it was a used heater misc parts that should be in a bag were just thrown in the big box battery for the igniter was installed but I needed a heater and about that time my brother and his wife showed up, pulled the heater out of the box turned it over to instal the brass gas fitting and there was one in place but way to big and I was having a hell of a time getting my deep socket on the fitting to remove it (Now why I didn't stop there and return it I don't know) Finally got the fitting out turns out they had run a flare fitting into a pipe thread but had not damaged the threads so with my brother help we connected it to my gas line (why the heck didn't I just take it back) turned on the gas I'm holding the pilot knob down he's pushing the igniter button about that time I said I smell gas and he said so do I and them boom we are both standing in a fireball lucky for us we only lost some eyebrows. Will finish this tomorrow
 
So I called complained loudly about the used defective heater got to the Menards store went thru the BS about returning/exchanging it with no receipt, had the guy open the box to make sure it was a new heater, gave him a piece of my mind about putting a used defective heater back on the sales shelf but it kind of went over his head as he was more concerned my not having a receipt. Went back to the shop office to see how the heater my brother and I installed it was working was 82*F so I set it dow some and went home, this morning when I went in to the office it wasstill at 892*F so I set it down some more will see what it is this afternoon this heater has more BTU;s I have it set about as low as it will go.
Good news is I got a start back on the PK
 
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