This is a really old thread, so this response may be useless but I’ll write it anyway.
I recently worked on a Lauson that is really a T-600 but is ID’s as an S-300 going by the tag on the motor. Irregardless, its a 6 horse twin. My motor was also stiff to turn over when acquired. Oiling the cylinder walls did not help. The problem turned out to be a seized upper crankshaft bearing. The bearing is shielded on both sides. Its been so long since this motor was used that the grease in the bearing solidified, making it impossible to turn. I removed the shield from one side of t he bearing and soaked it in lacquer thinner overnight to soften and wash out the dried up grease. The bearing spins easily now, and so does the engine. Might be something to check for if you haven’t done so nearly six years later, lol.
BTW my coil was no good due to the tar-like insulation either leaking out or being melted out. I replaced it with a John Deere pony engine coil that was available on Ebay. It works fine after altering the Eisemann laminations to make it fit.
Best.
PM T2
Thanks for posting Chris. I saw your pictures on FB. There is only one variety of the “John Deere Pony Coil”? I see them on e-bay and I should assume that the ones they have up there for sale listed as “John Deere Pony Coil” will be the one?