Fuel pump diaphragm

[theoldwizard2 2]

What is the part number for a genuine Kohler fuel pump diaphragm for a 310-8 with a Kohler 241 engine ?

 

Lots of aftermarket pumps, but the housing is in perfect condition.  Plastic body.   It has been sitting for over 20 years.

Edited April 17, 2021 by theoldwizard2

[theoldwizard2 2]

Opinions on this aftermarket diaphragm from Amazon ?  The old one had a cork gasket inside the pump.

 

 

 

Edited April 18, 2021 by theoldwizard2

[oliver2-44 8,837]

That rubber one looks like most of the original ones I’ve seen.  Good luck with it

[wallfish 15,912]

1 hour ago, theoldwizard2 said:

Opinions on this aftermarket diaphragm from Amazon ?  The old one had a cork gasket inside the pump.

Is the old diaphragm cracked or have a hole in it? The material they used for them is fairly thick so it's very durable. Since those pumps are mechanically driven instead of just pulse driven from the crankcase pressure, it should work even if it's stiff. The most common failure on those type of fuel pumps would be the check valves not sealing and allowing flow in both directions. I don't think the check valves can be serviced in those plastic pumps but I never had one of those apart either. If you can blow air backwards through the pump, the check valves are not sealing so the fuel would just be moving back and forth in the fuel line and not moving towards the carb. Or at least less of it would be getting to the carb depending upon how much or how little they are sealing

Edited April 17, 2021 by wallfish

[theoldwizard2 2]

No obvious hole but the metal plate actually has some rust on it.

 

I just replaced all of the fuel lines because they were dry rotted so I figured the fuel pump diaphragm could use it also.

[Bill D 1,596]

I made a metal plate and went this route.  Works well.  Cheaper than an OEM pump, and less likely to let gas in to the crankcase like the cheap pumps.  The pump in the picture is for a Kawasaki, however I prefer the Briggs 808656 pump.  Bill

[theoldwizard2 2]

8 hours ago, Bill D said:

I made a metal plate and went this route.  Works well.  Cheaper than an OEM pump, and less likely to let gas in to the crankcase like the cheap pumps.  The pump in the picture is for a Kawasaki, however I prefer the Briggs 808656 pump.  Bill

Good idea !  Where did you tap the pulse line into ?

 

The Briggs pump (I am pretty sure) is made by Mikuni.  Inexpensive and readily available.  Plus it has its own "breather" (no 4th line).

[oliver2-44 8,837]

Have you considered changing to an electric fuel pump.  I'm guessing your 310-8 has the gas tank under the seat and if the horse hasn't run in a while that it takes several second of cranking to get gas pulled to the carb.  With an electric fuel pump I turn my key to On for a brief second, then hit start.  My horse now starts as soon as I hit the start position.  I used the Facet1-2 psi pump from Air Craft Spruce Co. about $35 2 years ago.

Edited April 18, 2021 by oliver2-44

[theoldwizard2 2]

1 hour ago, oliver2-44 said:

Have you considered changing to an electric fuel pump.  I'm guessing your 310-8 has the gas tank under the seat and if the horse hasn't run in a while that it takes several second of cranking to get gas pulled to the carb.  

I understand. Even when almost new, it took a bit of cranking to get it to start (almost 30 years ago).

 

I am already spending too much to resurrect this beast !  Both front tires dry rotted and cracked to the point that they will not hold air.  I alway wanted one of these (I don't know why), and now I have one !

 

[Bill D 1,596]

Here's a picture without the pump that should help.  Bill

Edited April 19, 2021 by Bill D