As reliable as the Kohler engine is, there are a few things that the DIY rebuilder needs to consider.
- It is almost impossible to hear a rod knock with the stock muffler in place unless the knock is most pronounced. The cun cadet muffler is a good cheap alternative that makes the engine much quieter.
- In almost every case where a rod is knocking, the crankshaft is worn and must be reground. This is not expensive. About $60
- Crankshaft wear is a given as the aluminum rod bearing is harder than a traditional babbitt bearing.
- The crankshaft journal wear limit is something like .0015 inches.
- You CANNOT measure crankshaft journal wear with a caliper. You must use a micrometer.
- A loose rod bearing == low oil pressure. Lose enough oil pressure and the rod galls onto the crankshaft and the rod breaks.
- As the crankshaft spins, oil is forced into the bearing hole by virtue of it shoving down into the oil.
- It is vitally important that the proper oil level be maintained at all times.
- .020 undersized rods are now available for the K301 and possibly others.
As with most things, you can do it right or do it wrong. The right way means new valves, new plug, new points and condenser and possibly a new fuel pump.