STEPHEN - These little Kohlers are easy to rebuild. Not many parts at all to them. You really don't need many special tools. There's a link in the FAQ's to free prints of the latest edition of the Official Kohler K-series engine manual. Everything You need to know to rebuild Your 102's engine good as new. About the only thing special You'll need is a puller for the flywheel, a car engine harmonic balancer puller works, and a 3/8" torque wrench for tightening the head & rod cap bolts.
A good rebuild with OEM Kohler parts and all required machine work is around $350 to $400. You'll nned a piston which comes with rings, wrist pin & keepers, complete gasket kit, new connecting rod, and I'd replace the exhaust valve. If You haven't done a good tune-up in a while it would be a good time to rebuild the carb, install new points & condensor, spark plug, and air filter. While You have the engine out it may also be wise to install a new clutch throw-out bearing, teaser spring, and maybe the clutch disc, and rebuild the PTO clutch.
An automotive or small engine machine shop can check the cylinder bore to determine what oversize piston You need, and measure Your crankshaft journal to see if You need it ground undersize which means You need an undersize rod.
I suspect Your 102's engine broke a connecting rod, common failure. Hope nothing else was damaged. If You rebuild it's engine, or hire someone to rebuild it Your 102 should last another 20-30 years. It won't get Your snow plowed this next week but it sounds like You have a plan figured out for that anyhow.