just got a call from the machine shop, mine is done, price a lil more than I thought it might be, though
1. 1st time using these guys
2. we didn't discuss price before they started work
and 3. it has been about 3-4 years already since I had my last Kohler block machined, prices always go up not down...
What I found out about my current 12hp;
surprisingly did not need bored, has a 0,035" (3 and 1/2 thousandths) tolerance and it wound up at o.003"
valve seats cut
deck (top block surface) resurfaced just enough to clean up, something like 0.005 or 0.007"
I found a NOS OEM Kohler 0.003 oversize piston on FeeBay, there were several, wide price variation on the same part... so with that my tolerances should be exactly like a brand new engine
I also expected to have them tell me the valve guides would be "shot", but they weren't. I have new OEM ones here just in case.
the exhaust valve though was "shot"... got a new OEM one on Ebay again wide variation in price for same part... when comparing same part I look for the cheapest... no difference between a factory Kohler valve for this engine at $22 shipped vs a factory Kohler valve for $64... be careful how some are worded, many listed for sale are not factory parts.
I originally bought an Ebay kit but once they gave me the results of machine work I went back to Ebay and looked for that 0.003" piston... I dug out my 3-4" micrometer (NOT a caliper!) and the OEM one is 0.005" larger than the aftermarket "standard" one that I receivedin the kit... I'll use that one in the next build.... if I can get away with std sized parts.
but my very next Kohler build planned is a 14hp so it'll have to go onto teh shelf.... I do have another 12hp collecting dust that probably needs to be done..... but not a skinny base like Cub cadets take.