MICK M. - re rebuilt engine start-up. The carb adjustments listed here and other places are a guideline, further adjustment will be necessary once the engine is running and warmed up.
On the camshaft, yes, the pushrod for the points does make a groove on that lobe of the cam with extended usage. Replacing the cam was good. Yes, the cams from the K241 (10hp) thru K341 (16hp) are all the same lift & duration. There are some very old K241 cams that may not have the ACR mechanism on the exh lobe, and also may not have the lobe to run the mechanical fuel pump. But there aern't many of those left I'm sure.
The thing with the small ball bearings is a "Valve Rotator". Yes, they're heavier and more complex than a straight valve spring retainer but I sure hope you got the one working rotator on the exhaust valve. The retainer really shouldn't effect the tappet clearance since that is determined by the valve head-to-seat position and the valve stem length, but it's not a bad idea to check the clearance anyhow. The valve rotator does effect the compressed length of the springs so they do effect valve spring pressure both with the valves closed and open, but on a slow reving engine like a Kohler the pressure doesn't need to be very high anyhow.
Just make sure you timed the cam to the correct timing marks, don't use the marks for the balance gears...BT-DT. Also check the ignition timing as MATT G explains in the FAQ,s using a timing light. It may take a while for the engine to break-in and run properly.