Kohler L600 and L654, fuel pump info
OK, after a lot of research and dead end trails, I have the correct (I think) information on the fuel pump for the L600 and L654. After talking to Tom at Then and Now Automotive in Weymouth, MA, I discovered that the Kohler fuel pump is an AC with a slight modification. The bottom part (the part with the lever) is a typical AC pump with 6 new holes drilled 20 degrees off in order for the fuel lines on the upper half to clear the air filter and the generator housing. Looking from the top down, the top housing (unaltered) is twisted 20 degrees clockwise. This is accomplished by them drilling 6 new holes in the lower casting (the one with the lever).
After sending Tom pictures of the fuel pump broken down, he was able to make a new diaphragm with the pull lever rotated the appropriate 20 degrees to make it work. The Kohler has an oil seal that the Airtex may not have.
Since Kohler has discontinued the repair kit #241197, there was not an apparent place to get a rebuild kit. So, some people took an Airtex 572 pump (a copy of the AC pump for a Willys Jeep), drilled 6 new holes in the casting, twisted the diaphragm lever the 20 degrees, changed the drive lever, and reassembled. Now you do not have to do that. I sent Tom a lot of information on the Kohler fuel pump, and now he is going to list a repair kit on his website.
Tom sent me a repair kit, including every spring, valve, and rubber part, for $52.50.
Tom was super nice and very patient. I can highly recommend him. Please check out what he has to sell. He specializes in all kinds of odd parts, especially fuel pumps.