Dad gave me three supposedly O-K Kohler coils about 18 years ago, He was cleaning up his shop for his last auction. They sat on my workbench for a year or two till one day I'm mowing my yard with my vacuum unit, it's ignition on the K181 runs off the '72's battery. And over the course of the afternoon I had all 3 coils fail, couple just stopped working but the one failed in a spectacular fashion, by shooting up a geyser of hot oil out the center socket for the plug wire. And yes, the points were ruined too. I'd learned years before that parts store coils generally won't work long on Kohlers, after 10-15 hours of run time they get hot and most frequently the engine just stops. BACK WHEN I had the 72 & 129 one Sunday afternoon they were BOTH sitting in the back yard waiting for their coils to cool. Picked up two new Kohler coils that week after work. I'm pretty sure those two are still working. I bought a Bosch Blue coil from Dave Kirk while I was building my Killer K321 years ago.
When I think about how many thousands of hours of run time my two FARMALLS have I couldn't begin to guess how many millions of sparks each tractor has made.
Back on 2006 SON and I spent about every weekend down clearing out STUFF for the auction in Mid-July. I took my 129 down planning to sell it with Dad's herd of Cubbies. The M with the loader was as handy as a pocket on a shirt moving stuff, until it started not running well. I brought 5 gallons of my own good gas for the 129, and used it to start fires, etc, and poured the last couple gallons in the M. The gas we were using in the M was so stale I couldn't start fires with it even clicking my BIC in a puddle of liquid gas. THE M was much happier with my gas in it's tank. My gas of choice usually is Kwik -Trip 91 octane Recreational gas, 100% lead-free, no ethanol. It's made specifically to use in stuff that sits idle, not running for extended periods.