I bought 2 new O.E.M. plastic POS Kohler pumps a while back, one is on my freshly rebuilt M12. One thing about these new pumps; the flow direction arrow goes OPPOSITE the original so the fuel lines have to cross the pump rather than just going straight up into the carb... I guess there are 2 different versions of this pump currently available, one follows the original flow, the other is like the ones that I got... didn't realize this when I got them. seems (it has been a little while since I got these) like I remember 2 different PN's but no description of the difference, both showed as working on the same engines... found the difference the hard way. I HATE the "universal-ness" of them with the snap in plastic inlet and outlet fittings.
I do not have any old original Kohler pumps around at the moment, wish I did, now that I know they are available I'd order the kits and rebuild them
I did find someone on Feebay that has a pile of NOS ACDelco fuel pumps for the KTs and Magnums... around $45 a pop. These are new in box but 30+ years old and metal bodied instead of plastic. I got one for my KT19 on my Ariens, made a big difference in how it runs. The original pump which I pulled off was even plastic/ this tractor and its engine are from about 1985.
(no I am not saying the metal body has anything to do with functionality, just surprised that I was able to find something like that)