I bought a 74 112 with the 47" deck last year and mowed all summer with it. So far I replaced all spindle bearings, the pto bearings, belts, and various pulleys on this machine. Welded cracks in the draft bar and still need to finish repairs in the mower deck.
Even though the engine ran well as far as it always started, it used a lot of fuel, and burned approximately one quart of oil per half acre. I removed the engine and asked my brother to help me rebuild it since I was in a car accident and got a broken leg a week after pulling the engine.
Our findings so far:
cylinder bore was .030 over and too worn to hone
crankshaft was in good shape, was ground .010 under and is still in spec
valve stems, guides, and seats worn
carburetor throttle shaft worn so bad that I don't think a bushing kit will fix
crank bearings look good
crank balance gears were removed on previous rebuild
New parts purchased so far:
valves and guides
standard size piston and rings
kohler manual for K series engines
Today we took the engine block to a local machine shop. They obviously didn't want to do the job. He said the bore was too worn and then proceeded to say that he bored them to .060 over in the past and also bored them out to fit a chrysler piston from a v-8 316 cubic in engine. We took the parts back home and got ahold of an old friend that bores motorcycle engines. He's agreed to bore it and install a sleeve back down to standard size. I'm going to try to be good on keeping our progress posted so others can use it a resource. I'm sure I'll have questions for the experts on this forum as well and hopefully can get some good interaction with members.
Attached are pic of the tractor, and the engine and flywheel. Note the fins packed with sludge. The rings and bore showed that it was overheated.