Kohler K161 7 horsepower engine with a pulse operated fuel pump. I took it apart and cleaned it several weeks ago, reinstalled it, and had the engine running like a top. Started right up the dozen or so times I tried it, and ran it around the yard several times for a total of probably an hour or so. So it was working, but since then I removed and painted all of the sheet metal on the lawn tractor it's in, put everything back together, tried to start it last night, and the pump is not working. Next step, obviously going to disassemble, clean, and inspect it again, but thinking ahead to what if it still doesn't work. One option might be to make a plate to fit over the opening in the crankcase with a neck on it to attach a pulse type fuel pump for a current engine? Or an electric fuel pump. But there are multiple pumps available, both pulse and electric, so how do I determine what size I need, or how much does it matter? Will these pumps bypass such that the needle will prevent it from dumping too much fuel to the carburetor, or do I have to somehow come up with the exact size pump I need to match the fuel consumption of the engine?

Putting my Central Pneumatic(Harbor Freight 90234) back together and I am perplexed about how tight the check valve is supposed to be. Upon starting to thread it in it goes smoothly, but when it is slightly snug I can use an open ended or adjustable wrench. I can turn it a bit more but it gets to the tightest point that it wont line up in the proper position for the copper tubes. Just how much am I suppose to lean on this thing. I am afraid to destroy the treading on either the valve stem or the tank hole.