To avoid these ads, REGISTER NOW!

17.5hp Kohler Command Fuel Pump

MacMcMacmac

Well-known member
Joined
Oct 21, 2014
Messages
1,592
Location
canada
Does anyone know the Freemason's Handshake necessary to source the proper fuel pump for a 17.5hp Kohler Command?

I took every number I could find off of this motor and went to the local small engine sales and service shop and the counter guy couldn't find the proper one, saying he did not have enough information. I even told him the application and he couldn't manage it. I bought one off of Amazon about a year ago and I had to mess with the lever to get it to run so that it didn't pump so hard it flooded the motor , or didn't pump enough to run the engine. I could order another one and go through that again, but I don't want to. I broke the fuel line fitting pulling out an inline filter that didn't seem to want to work properly. I would mount a tank behind the seat and gravity feed it if I could but I think that would just open a whole other can of worms.
 
To avoid these ads, REGISTER NOW!

laser3kw

Well-known member
Joined
Nov 17, 2012
Messages
7,276
Location
northen IL
if the mechanical pump is that finicky, look at using the crankcase pulsed pump that is used on a wide varity of motors. My Kohler 17hp uses that style.
kohler fuel pumps.jpg
 
OP
M

MacMcMacmac

Well-known member
Joined
Oct 21, 2014
Messages
1,592
Location
canada
Sorry to resurrect an old thread but I figured I'd post here since its on the same subject. I am installing a pulse pump for this motor since the second lever style pump in a row refuses to move any fuel. Lesson learned. The guy at the small engine shop says I need to use intake pulse to run it, not crankcase. This is unfortunate since I have two useless lever pump bodies I could empty out and use one of the fuel barbs to provide the pulse. I figure I could mount the pump high enough to keep the oil out. If that isn't a good idea, would tapping into the existing breather line at the tappet cover provide enough pulse to actuate the pump with the breather line still hooked up to the inlet?

I had a crazy idea that pulling the guts from the lever pump and letting crankcase pressure work on the diaphragm inside it to make it work like a pulse pump, but I thought it would need a return spring to bring the diaphragm back in after the high pressure pulse from the crankcase.

All of this is moot until I figure out why the machine is suddenly getting no power anywhere. I suspect the 4 pin relay I put in has failed and there is no NC connection that was provided by the OEM 5 pin relay, so maybe that's an easy fix.
 

laser3kw

Well-known member
Joined
Nov 17, 2012
Messages
7,276
Location
northen IL
What year and type machine is this? look for a in line fuse some where. I have seen them by the starter solenoid and behind the dash area. Most are the automotive spade type fuses.
I will take a look at my Zero turn and see where it gets its pulse from (tomorrow)
 

gregs

Well-known member
Joined
Mar 16, 2007
Messages
1,609
I have seen numerous people misdiagnose the fuel pump when in fact it wasn't getting power to the fuel solenoid on the carb. If the fuel solenoid doesn't open and the bowl is full, there is no where for more fuel to go so it looks like the fuel pump isn't working.

As for the pulse type pumps, the pulse comes from the crankcase. There is no pulse in the intake. Some engines have a hose connected to the valve cover, some have a barb on the side of the block. Kohler has a metal fuel pump block off plate that I have taped and put a barb in it to use the fuel pump opening. If you can manipulate an old pump housing to do the same it will work fine.
 
To avoid these ads, REGISTER NOW!
OP
M

MacMcMacmac

Well-known member
Joined
Oct 21, 2014
Messages
1,592
Location
canada
Hi guys, thanks for the replies.

The mower is a JD L110, so early 2000s. I could feel the solenoid opening, and it's a new carb, so I am confident that is not the problem. I could also "prime" the carb by blowing into the tank (yum) and waiting a few seconds. I could get the motor to start that way but it ran dry very shortly afterwards. The kicker is I can pull the pump, move the arm by hand, and the pump spurts fuel quite enthusiastically, then it goes awol once it's back on the engine. At any rate, I'm done with it. I gutted one of them and plugged the top barb outlet, so I will hook into that for the pulse. I think the small engine shop guy was telling me to hook it up after the throttle plate to use engine vacuum to pull the diaphragm to move the gas.

The electrical will succumb to my efforts eventually. I am somewhat confused as to why there are no lights or engine timer when I switch on the ignition, as they are fed right off the ignition switch (replaced, no change). This leads me to think the power lead into the switch itself might be broken. I have not had the weather to get deep into the electrics (open air repairing *****), but the wiring is pretty simple.

Before I got to do any of this I had to pull the seized starter motor (new, Amazon) to find absolutely no lubrication on the top shaft bushing.

Hmmm, Amazon fuel pump, Amazon carb, Amazon starter...I am sensing a pattern here.

I also rebuilt the blades spindles, put a used floor pan on it, after blasting, priming, rocker-guarding and painting it, plus new blades. It's the most expensive $300 riding mower on Earth. If it wasn't for a friend who can't really do the manual labour involved in taking care of her yard, I'd have put an axe to it by now.
 

gregs

Well-known member
Joined
Mar 16, 2007
Messages
1,609
Also check the fuel line back to the tank and the pickup. Any type of air leak can cause these pumps not to "****" very well. Down here we have a beetle that will bore tiny holes in the fuel line. It doesnt leak gas that you can see, but it will sure leak air and cause the pump not to be able to draw fuel. More problematic on top pull fuel tanks.

The vacuum pump has to have a "pulse" to make the diaphragm work. Negative pressure from the manifold wherever you get it from will not work. It needs the "pulse" of crankcase vacuum "piston going up and down" to move the diaphragm in & out so that it draws fuel on one side and pushes it out of the other.
 

PassnThru

Well-known member
Joined
Jan 5, 2010
Messages
6,512
Location
Bowling Green KY
I'm watching this - I've got a L110 that was purchased I believe in 2003. Mine just hit 800 hours last night and is apparently in a lot better shape than that one. I'm still running the original carb and starter and fuel pump for that matter. Sure - some spindle bearings and belts and pulleys but the engine and electrical really hasn't been touched.
 
OP
M

MacMcMacmac

Well-known member
Joined
Oct 21, 2014
Messages
1,592
Location
canada
Well, someone must have lit a candle somewhere, since the Bosch 5 pin relay I bought and installed fixed every electrical problem instantly. The only issue is that I can now cut in reverse without holding down the override button on the dash, in fact, it now kills the motor if I do. I'll take that, since I always hated that feature anyway. I guess JD has their own relays on top of everything else.

I hooked up the pulse pump and got no start. Then I realized I needed a clamp on the output tube, since gas was coming up past the hose. Then I realized I had taken the hose off at the carb to check for fuel flow last time and forgot to hook it back up again. 😒 Well, at least I knew it was pumping....

So after my self inflicted problems, and after washing the gas off of the frame with a garden hose, it managed to start and idle like new, if a bit smokily. This mower was run hard and put away wet for many years. I bet I gave it its first oil change a few years ago when the widow down the street owned it. The floor pan was rusted through, so much so, I had to be careful getting on and off, and had to check where my feet were resting while running it. The vibration and moaning when I engaged the blades told me the bearings were shot in the deck from the first time I used it. When I pulled the blades, they looked like boomerangs. When I pulled the spindles, loose balls and bearing races dropped out onto the ground. I swear her brother in law who "borrowed" it for a few years was mowing ditches on the side.

Still, it ran and started when she owned it. When I left the neighborhood, the widow offered it to my friend for $300. I figured it ran ok (ha ha) and I was sick of push mowing her 1/2 acre yard (she has health challenges), so I figured she should go for it and I would fix up any issues it had. Now that it's running well I guess I can expect the engine to throw a rod, or the infamous K46 ****** to dump its guts. It only has 380hrs on it.
 
To avoid these ads, REGISTER NOW!
Top Bottom