Over Bore Question
 

I finally was able to get out into the shop today with the heater and be comfortable to do some work. I was able to finally check the bore wear on my K301. After looking at the measurements, it looks as if the bore has been wore to a .020 size from standard. It is very consistent top to bottom and yes I did check it at the six locations as per the Kohler manual. 3.3950 was the average measurement. My question is obviously either .030 over is what I will have to have it bored too, or, Seeing how the K301 and K321 are essentially the same except for bore, can I just punch it out and go with a standard K321 piston and rings in it. I was not sure if the blocks of each engine were the same? Does anyone have differing view or suggestion. This is the 128 I got from my grandmother so I don't have an issue such as having a 14hp piston in it as it will never go anywhere but here then to my daughter way way way down the road :)...
Thanks for all the input.
DWayne

Think I found the answer to my question. There seems to be a balancing issue in regards to the larger piston of the 14 and 16hp pistons in. The K301 and K321/341 cranks have the same stroke, but are different due to being balanced for their respective pistons. A 14 or 16hp piston can't be used with a K301 crank. It will vibrate too much and the rod could have a catastrophic failure. OK looks like I'll be boring it .030 over or sleeving it.

Not to mention not all of the K301 blocks can safely be bored to the K321 standard bore size and leave sufficient cylinder wall thickness.

That was my main concern and didn't know how to tell if one was thick enough or not.