Kohler Fuel Pump Question

[Horseoholic 169]

Hey folks , need some opinions on a replacement fuel pump for my 71' Charger 12 automatic , It's got the Kohler K301 , looks like in it's life span the PO replaced the fuel pump at one time with a plastic type which has ran good for the years that I have owned it , Now the pump has failed as I use the clear fuel hoses and can see when cranking the engine I can see fuel on the inlet side and nothing being sent to the carb. on the outlet. Question I have for you all is after searching on the web for a replacement pump I'm a little gun shy after reading some of the reviews on alot of the fuel pumps listed for sale (all plastic styles) and was wondering if anyone may have had luck with a particular brand of pump ? I would like to keep it as a mechanical fuel pump instead of converting it to electrical ( just my preference ) any insight is greatly appreciated . 

[Achto 27,594]

13 minutes ago, Horseoholic said:

any insight is greatly appreciated .

 

I've had good luck with the Rotary brand plastic pumps about $50. The Kohler pump is good too, still plastic and about $150

[953 nut 55,280]

Check your oil and don't attempt to start the engine until you KNOW there is no Gasoline in the engine oil. A failed diaphragm in a mechanical or vacuum fuel pump is a primary cause of failure and will allow gasoline into the crankcase. That is why many of us have converted to electric pumps.  

If you don't want to go to an electric fuel pump I would suggest you get a used metal fuel pump and a rebuild kit from https://www.a-ztractor.com/ or any other source of your choice.

[ri702bill 8,327]

45 minutes ago, 953 nut said:

Check your oil and don't attempt to start the engine until you KNOW there is no Gasoline in the engine oil. A failed diaphragm in a mechanical or vacuum fuel pump is a primary cause of failure and will allow gasoline into the crankcase. That is why many of us have converted to electric pumps.  

If you don't want to go to an electric fuel pump I would suggest you get a used metal fuel pump and a rebuild kit from https://www.a-ztractor.com/ or any other source of your choice.

 

Excellent advise - oil diluted with gasoline will ruin the engine. IF you find that there is gas in the oil - fix the pump issue, drain and refill the oil. Check to see the function of the pump, AND check the oil for gas again. You may wish to change the oil twice...

Bill

[WHX?? 48,823]

All of my electric pump tractors start instantly so i get it but I like to stay mechanical too. 

Trouble is I have had rotten luck with the plastics so I often go out of my way to save the metal ones. 

If you got a couple years out of a plastic you did good. I get a couple of weeks out of them. 

Guess all a guy can do in absence of a metal one is to stock.up on the plastics and watch the oil... or go electric. 

[Horseoholic 169]

Thanks All , I do have an old metal fuel pump that came off of the K241 that I rebuilt from my 1057 , It is in desperate need of a rebuild , I wasn't sure if there was any rebuild kits for these old pumps , are the rebuild kits that you all may know of pretty reliable and seem to be installed with no issues ? Thanks again guys .

Edited March 10, 2023 by Horseoholic

[WHX?? 48,823]

Yes Then and Now auto has them. Very complete kits. 

@Achto can you get him a ? 

You can also find them in the jungle or fleabay cheap but they ain't worth a hoot. 

[Mike'sHorseBarn 2,998]

Since we're on this subject does anyone know of a source for vacuum pump diaphragms other than then and now auto? I've used a couple if theirs and they are too thin and weep gas around the edges. That's even after I true up the surfaces of the pump.

Edited March 10, 2023 by Mike'sHorseBarn

[rjg854 11,376]

for what model?

 

Buckrancher has them for the 8hp pulse vacuum pumps.

Edited March 10, 2023 by rjg854
add

[Achto 27,594]

Here is a link to Then & Now Auto.

 

https://www.then-now-auto.com/product-category/fuel-pump-kits/kohler-fuel-pump-kits/ 

[Mike'sHorseBarn 2,998]

8 minutes ago, rjg854 said:

for what model?

 

Buckrancher has them for the 8hp pulse vacuum pumps.

 

That's what I need it for the 8 hp models.

[Handy Don 12,233]

2 hours ago, Mike'sHorseBarn said:

Since we're on this subject does anyone know of a source for vacuum pump diaphragms other than then and now auto? I've used a couple if theirs and they are too thin and weep gas around the edges. That's even after I true up the surfaces of the pump.

If it's weeping after the two surfaces have been “trued” there is something else going on.

 

Installation of the diaphragm is a bit counter-intuitive since the material must not be “taut” when the pump is screwed together. Instead, it must have slack at the center that can pulse in and out easily. That means there will be small wrinkles in the diaphragm at the edges as you start to assemble it.

 

The material must be thin to allow it to compress sideways along the seam as the pressure of the closing faces flattens out the wrinkles.

 

If the material is too thick, it fails both by not having enough flex for the vacuum to cause pumping action and by not being able to smooth the wrinkles.

Edited March 10, 2023 by Handy Don

[ri702bill 8,327]

1 hour ago, Handy Don said:

and by not being able to smooth the wrinkles.

Unlike trying to get wrinkles out of one's Birthday Suit....

[peter lena 8,632]

@Horseoholic  been using a CAR- BOLE  electric pump for years , no problems at all , also wired in a single green led light at dash , to verify operating function . pricing was also good , very reliable . look it up , cost me about $ 20 , try amazon , pete

[Bill D 1,922]

I've done this conversion in recent years.  Use a Briggs or Kawasaki pump.  Homemade mounting plate. Works great.

[peter lena 8,632]

@Horseoholic  https://www.amazon.com/CarBole-Universal-2-3-5P-S-I-Operating-Self-Priming/dp/B01IR6BNKY/ref=asc_df_B01IR6BNKY?tag=bingshoppinga-   this the one you want , low pressure  part# 42 S , sorry about the other info I  sent you , mounted it up front just in front of engine , or you can mount it close to tank . pete

[Handy Don 12,233]

On 3/10/2023 at 12:11 PM, ri702bill said:

Unlike trying to get wrinkles out of one's Birthday Suit....

Thought about a response.

Naah.

Edited March 11, 2023 by Handy Don

[Mike'sHorseBarn 2,998]

6 hours ago, Bill D said:

I've done this conversion in recent years.  Use a Briggs or Kawasaki pump.  Homemade mounting plate. Works great.

 

 

I've been wanting to try this.......

[WHX?? 48,823]

I've had no problems with Buckrancher's Mike. 

8hp??? All of mine have been on 7s. 

[Bill D 1,922]

4 hours ago, Mike'sHorseBarn said:

 

 

I've been wanting to try this.......

Here's another picture to help you make a mounting plate for yourself.  Good luck with it.

[Mike'sHorseBarn 2,998]

14 hours ago, WHX?? said:

I've had no problems with Buckrancher's Mike. 

8hp??? All of mine have been on 7s. 

 

Yea all my 8's have the vacuum pump. All my 7's have been mechanical so far. 

[EB-80/8inPA 1,648]

On 3/10/2023 at 9:20 AM, Achto said:

Here is a link to Then & Now Auto.

 

https://www.then-now-auto.com/product-category/fuel-pump-kits/kohler-fuel-pump-kits/ 

Thanks for that link.

They show four options.  Does anyone know for certain which one fits a K301 spec #4712B?  TIA.

Edited March 12, 2023 by EB-80/8inPA

[WHX?? 48,823]

Only way to know  is pull the pump apart and look at the diaphram to lever connector. Most of the ones we use have the T slotted end, the most vommon. There is more info on that site on identifying them. 

[WHX?? 48,823]

23 hours ago, Mike'sHorseBarn said:

 

Yea all my 8's have the vacuum pump. All my 7's have been mechanical so far. 

That's weird. I might have it backwards tho. Does your 161s have the offset lever Mike? 

[peter lena 8,632]

@Horseoholic have these on my engines ,https://www.amazon.com/EVIL-ENERGY-Return-Petrol-Aluminium/dp/B08JJ128LN?th=1 , that vertical hose to carb area is a perfect spot for it  , also use clear . vinyl fuel lines , so you can see the fuel hold . arrow on valve facing UP TO CARB  , verifies  fuel hold to carb , also ues dark green squeeze clamps , for a size to size fit . if your pump is faulty , get that done first , or combine the fix , pete