fuel pump for small engine
#1
07-20-18, 05:09 AM
fuel pump for small engine
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?
#2
07-20-18, 05:59 AM
Member
Is there ground wire involved with the fuel pump. Did the new paint destroy the ground connection?
#3
07-20-18, 06:10 AM
Thank you, but no, the original pump is a pulse type, so no wires. There is landing on the side of the crankcase with an opening maybe 1/2" by 3/4" that the pump bolts over. And that concept has worked fine up to now, so unless I can repair it I was thinking that a plate over that opening with a nipple welded or threaded into it and a vacuum hose from that to a modern pulse type pump may be the most efficient way to go. Probably better than an electric one, but figured an electric could be option two if the pulse didn't pan out. I think it will work fine, but not sure how to figure what size I need, or maybe it doesn't matter much.
#4
07-20-18, 07:58 AM
I would just put a small electric turbine type on it. To be safe put a relay in the switched circuit. The float needle can handle 1 lb of pressure pretty easy and you can match the size to what you use in an hour to mow, etc.
#5
07-20-18, 10:49 AM
Forum Topic Moderator
The aftermarket electric pumps from parts stores are fine, just make sure you get one for carbureted engines, not fuel injected. Personally I'd get a new fuel pump like your original. They were some of the most reliable fuel pumps found on small engines and I haven't had much success with the electric ones lasting for very long and the pulse ones aren't as good as the old Kohler mechanical ones either.
#6
07-20-18, 11:12 AM
I still have to pull mine back apart and see if I can get it to work, but, if not, yes, my preference is definitely to stay with an original replacement. The problem though, so far anyway, is that I have not been able to find one. Mine looks exactly what I have seen of lever operated pumps except that mine is pulse operated, with no lever, and as far as I can tell, peering through the small opening in the crankcase where it attaches, there is no lobe to actuate a lever type pump.
#7
07-20-18, 11:19 AM
Member
They were some of the most reliable fuel pumps found on small engines
#8
07-21-18, 04:42 AM
We'll keep our fingers crossed, but I think that I'm back out of the woods on this for now. Pulled the pump off last night, took it apart, cleaned it, put it back on, and she's running again. When I took it apart the first time the diaphragm had a real hard crust on it, with noticeable thickness, varnish from the gas that had been left in it, and I knew that I did not want to damage it because I imagined no way I would find one, so just cleaned it as good as I could with a tooth brush. Well, the fresh gas that I ran through it a few weeks ago softened that varnish, leaving just a powder that I was able to completely brush off the diaphragm, and left a sticky goo on the discs that had one of them somewhat glued down. Hopefully that's the extent of it because she otherwise runs great.
