Kohler 8 HP fuel pump years/types?

[ebinmaine 67,568]

What year did Kohler use the vacuum diaphragm vs mechanical lever in the 8 HP engines?

 

@Handy Don has a 64 with a lever. Trina's 867 is a vacuum...

 

Apparently they were intermixed?

Or is one of our engines older/newer than it should be?

 

 

[ri702bill 8,327]

And, why not add a 3rd variety. Both my 702's came with a lever arm and an additional external arm. That additional arm is a priming device to activate the pump with the engine off. I have one added to the 854 and use it a lot for easier starting.

Bill

[Achto 27,597]

1 hour ago, ebinmaine said:

Trina's 867 is a vacuum

 

My 867 has a mechanical pump with a primer handle.

[953 nut 55,290]

I have no idea when the primer lever fuel pumps were offered on Wheel Horse but my 1055 had one when I bought it as did a couple of the 953s. Seems like the mid-1960s was the end of the line for that type of pump. I have used them on later models also but now I'm using electric fuel pumps on everything except "Faithful Restorations".

Here is what I could find on Miller's site.

 

The purpose of the older and now obsolete OEM Kohler mechanical fuel pump with the manual hand lever (thin metal piece that hangs down under the pump body) is for when the engine runs out of fuel, after refilling the gas tank, it takes less time to manually prime the pump and refill the carburetor with gas by working the lever by hand than it would to crank the engine for a long time so the fuel pump can draw fuel from the tank and deliver it to the carburetor. This was a nice feature, especially on engines with a rope or recoil starter! It also saves wear and tear on the electric starter motor from cranking the engine for a long time, which could eventually burn up the starter or drain the battery.

 

---

FYI - Virtually of all of Kohler's single cylinder cast iron block and opposed twin cylinder engines come with a lobe on the camshaft to activate the mechanical fuel pump. The fuel pump installs with the lever positioned upwards. And if there's no provision on the side of a [single cylinder] block to mount a mechanical fuel pump, a 3/4" center hole and two 1/4" bolt holes can be drilled, and the 1/4" holes tapped for 1/4-20 UNC threads to mount a mechanical fuel pump. Use a fuel pump mounting gasket as a templet to drill the holes

[Handy Don 12,233]

3 hours ago, ebinmaine said:

Or is one of our engines older/newer than it should be?

 

This has me thinking. Gonna get the build spec today and check it out.

[ri702bill 8,327]

55 minutes ago, 953 nut said:

The purpose of the older and now obsolete OEM Kohler mechanical fuel pump with the manual hand lever (thin metal piece that hangs down under the pump body) is for when the engine runs out of fuel, after refilling the gas tank, it takes less time to manually prime the pump and refill the carburetor with gas by working the lever by hand than it would to crank the engine for a long time so the fuel pump can draw fuel from the tank and deliver it to the carburetor. This was a nice feature, especially on engines with a rope or recoil starter! It also saves wear and tear on the electric starter motor from cranking the engine for a long time, which could eventually burn up the starter or drain the battery.

Around here, somehow over the years and 3 generations of family WH owners, the hand lever has always been referred to as "The Twicker" , as in "Don't forget to use the twicker before starting the 702."

[squonk 41,145]

This pump is on my original 702 engine.

 

 

You can see the primer lever on this pic from my 701

 

Edited March 22, 2022 by squonk

[953 nut 55,290]

What can I say, a couple of basic tools and a few minutes and the primer pump can be fitted to any fuel pump equipped Kohler engine. I found a thread that was done several years back on this same subject. Same question remains unanswered.       

 

[pfrederi 17,741]

Not sure why it is of interest but there was no specific Change over "date".

 

There are at least 748 spec number K181s Vac pumps show up from the earliest spec number 30100  (First WH was 30108 using vacuum) to one of the last 30845  (last spec Number I had variations on is 30848).

 

They did seem to be used a lot less frequently after 30446.  Earliest cam operated pump seems to be 30265 built for Daffin corp.

 Bottom line between what the buyer wanted or what Kohler had on hand decided what you got...  Not sure why all this matters  they all work...

[Handy Don 12,233]

I accidentally posted this to the old thread. Moving it to this one...

 

This is a lever-actuated pump from my K181 on an 854 (as @ebinmaine noted). I am pretty sure it's not of original vintage since its check valves are not removable; you can see the indented "Vs" where the cover body was "flanged" over their edges to hold them.

The cover with the check valves has the inlet on the right and the outlet on the left. Both had debris preventing them from sealing properly but once gently cleaned they worked fine. You can see sand and other junk on the diaphragm. 

Diaphragm replacements are available (complete with plunger and upper and lower disks, but I'm not yet sure how to separate/re-connect the diaphragm and the actuating lever.

 

Edit (and also thanks to @pfrederi): In the Kohler maintenance manual I just found that pressing down on the diaphragm disk and rotating it 90º releases it from the lever!

 

[WHX?? 48,828]

4 hours ago, Achto said:

 

My 867 has a mechanical pump with a primer handle.

My 867 just has a mechanical ... no primer.

857 has a vacuum. 

Me thinks it was whatever on the assembly line that day in no particular year  & whatever they had the most of to use up. Damn the spec # who's gonna know & it will run just fine it's new.  Just get it crated the Ponds need motors. 

Same with a dealer repair in the day when dealers stocked pumps. 

 

A conversation in 1966. 

 

Small Engine Mechanic Frank: Hey parts guy I need a mechanical fuel pump

Parts Counter Guy Harry: We're out of them use a vacuum one... will work fine last a long time. 

Edited March 22, 2022 by WHX??

[pfrederi 17,741]

16 minutes ago, WHX?? said:

My 867 just has a mechanical ... no primer.

857 has a vacuum. 

Me thinks it was whatever on the assembly line that day in no particular year  & whatever they had the most of to use up. Damn the spec # who's gonna know & it will run just fine it's new.  

Same with a dealer repair in the day when dealers stocked pumps. 

 

A conversation in 1966. 

 

Small Engine Mechanic Frank: Hey parts guy I need a mechanical fuel pump

Parts Counter Guy Harry: We're out of them use a vacuum one... will work fine last a long time. 

  Curious what are the spec numbers of the engines

[ebinmaine 67,568]

10 hours ago, pfrederi said:

Not sure why it is of interest but there was no specific Change over "date".

 Bottom line between what the buyer wanted or what Kohler had on hand decided what you got...  Not sure why all this matters  they all work...

TBH it was just purely out of curiosity. 

I'd never heard of a vacuum signal type fuel pump until Trina's 867 got here.  

I assumed.... Yeah that word....

That it was a standard on anything 60s.  

Nope.  

 

 

[WHX?? 48,828]

9 hours ago, pfrederi said:

  Curious what are the spec numbers of the engines

My thoughts exactly  Paul  but a line boss in the day coulda threw  that all out the window just to get motors shipped. much as it is today.  'twas all about the almighty dollar back then as much as it is now. 

[Handy Don 12,233]

39 minutes ago, WHX?? said:

My thoughts exactly  Paul  but a line boss in the day coulda threw  that all out the window just to get motors shipped. much as it is today.  'twas all about the almighty dollar back then as much as it is now. 

Stuff in inventory doesn't do any good. Stuff on the loading dock going into a truck--that's good.

[Lane Ranger 10,968]

My 754 has a fuel pump that looks on outside like a regular Kohler fuel pump but it is a compression pump with a diaphragm inside and no cam arm.   Only one I have ever seen like this.  When working on motor in Florida to revive this tractor we took

pump apart and cleaned.  Pump was slow to get operational but it not pumps fine ( even with a bad head and head gasket that needs to be changed.  

[Handy Don 12,233]

25 minutes ago, Lane Ranger said:

Pump was slow to get operational but it now pumps fine

Just using a rebuild kit on a K181 lever fuel pump.

At first I thought it was the wrong kit since the holes in the diaphragm didn't initially line up with the holes in the body (too spread out).

Reading between the lines in the Kohler manual, though, I realized that "scrunching" the diaphragm puts enough rubber into the pumping chamber to allow the piston to flex it when pumping without tearing it. That's why the manual instructs tightening the screws while holding the pump lever in its fully actuated position. 

 

Also, I gently emory papered the faces of the pump body on a flat plate to flatten them--like a cylinder head--because there was unevenness that I suspect was preventing a good seal and was the real cause of the leak I'd been seeing.

Edited March 26, 2022 by Handy Don

[953 nut 55,290]

8 hours ago, Handy Don said:

Reading between the lines in the Kohler manual, though, I realized that "scrunching" the diaphragm puts enough rubber into the pumping chamber to allow the piston to flex it when pumping without tearing it. That's why the manual instructs tightening the screws while holding the pump lever in its fully actuated position.

      I know how embarrassing it is to admit to having read instructions but it happens to all of us now and then. You are a better man than most for having admitted it.  

[wallfish 17,011]

20 hours ago, Handy Don said:

I realized that "scrunching"

Engineering term?