T1760 Mechanical Fuel pump question

[Leonidas]

I recently replaced the fuel pump on a riding mower [17HP water cooled Kawaski engine], model T1760 as no fuel was being pulled from the fuel line. The engine would start and run after injecting starting fluid directly to the Carb intake. Determined the fuel can be pulled (siphoned) up to the intake on the fuel pump. Took the new pump out and checked the rod that I suspect moves in and out as part of the pumping action. The rod moves freely in and out by my hand. When cranking the engine I noticed the rod never moves in or out making me think there is an internal problem requiring further investigation/tear-down.

So my question is; Shouldn't that rod be moving in and out when I crank the engine? If yes, what is the cause and solution?

 

[SidecarFlip]

The Kawasaki on my zero turn uses a vacuum pulse fuel pump. Never knew Kawasaki used a mechanical pump. Mine is a 24 horse however.

 

[Dave_eng]

According to Messicks your T1760 uses a mechanical fuel pump.

The rod should move in and out as the engine rotates.

Cannot tell how the mechanism works.

More details on the engine model might help but clearly something is not right.

Dave

 

[Leonidas]

Did not want to spend $100+ for the service manual as the mower belongs to my neighbor [recent widow] that I'm trying to help since my retirement last year. Will take a closer look at that Kawasaki engine to determine the amount of movement on that rod. The engine label shows the following: Family ID SKA437U1G2RA , code FD501V-AS01, E/NO FD501V 090984

Interestingly enough, I can tell the fuel pump was replaced before. The manufacturer run date = 1995-2001. The Kubota S/N = 35391. The Kubota manufactured date = 0697. This is my first 17HP liquid cooled two cylinder engine to work on.

 

[Dave_eng]

I have looked at Kawasaki's parts illustrations for the engine.

So far it is not clear to me where the fuel pump attaches to the engine.

On some FD series manuals ( but not the 501 which I cannot find) the fuel pump is low on the engine and is likely being pulsed by a lobe on the cam.

I would expect the movement of the push rod to be small.

I would expect that inward pressure would have to be applied to the rod and then held as the engine rotates to detect any in-out movement

Dave

 

[Leonidas]

Searching more using the Kawasaki engine model FD501V-AS01 lead me to the following WEB site that has good details on part numbers, etc.
https://weingartz.com/assembly-diag...troke-engine-fd501v-carburetor/4417-316-49609

Found out the rod for the diaphragm mechanical fuel pump moves very little. I'm now at the realization that what amount I can suck or blow through those fuel lines and filter is not a good measure of how easy the fuel flows in those old hoses. Sooo... time to replace the fuel filter and lines (even though I was able to siphon fuel). I remember the old fuel pump had brownish color liquid coming out when I removed it. This also means I need to drop the carb bowl for content inspection and possible clean out. Found out the mower was sitting in the garage for a few years untouched. Back to basics. stay tuned..

 

[rentthis]

If the engine sat for an extended period, there is likely varnish build up in the carb jets. A really good cleaning might be all it needs.

 

[GeoHorn]

My BIL had a Kawasaki engine on his lawn tractor which he asked me to “look at” as it would not start.

The fuel smelled like varnish and I asked him when was the last time he’d used it. “Oh... ‘bout 4 years ago... Couldn’t get it started last year and I gave up.”

I added fresh gasoline and it started on the third “pull”....ran sorry for about two minutes and then revved right up and was good-to-go.

 

[Leonidas]

Started to replace fuel lines and filter but stopped so I could work on getting that carburetor out first thinking I would need a kit (gasket, etc.) to order. What a task! Had to remove the radiator (sits on top) and covers so I can see the linkage and get access. Should be fun putting it back together. Anyway, no luck yet in finding a carburetor kit or replacement carburetor for that FD501V-AS01 engine. Should be expected for a 23 year old model.

Will check out that site "Messicks" mentioned earlier in this thread. A few sites I found showed "Not Available" for carburetor or kits. May have to just clean the best I can and slap it together. more to follow...

 

[Leonidas]

Carburetor didn't look all that bad, but since they can be tricky (my limited experience) I decided to order a replacement ($29 - Annpee AM128355 Carburetor with Gasket Kits for Kawasaki FD501V) while cleaning the old one. Two days later it arrived and installed. Also replaced all fuel hoses. Removed/inspected gas tank and removed small wooden stick, small plastic piece and a 8" strip (one inch wide) of yellow plastic tape at the bottom of the tank.

Still would not pull fuel into [new] fuel filter. Unable to blow air into gas tank. Took tank and fuel cutoff switch out (again) and found the fuel cutoff valve needed to be fully turned (I heard the click) on. Will continue today.. Fingers crossed. stay tuned..

 

[Leonidas]

No luck. Engine cranks and starts when I spray starter fluid into Carb intake. No gas getting sucked into the fuel filter.

Is there a fuel pump vacuum pressure tester out there??

 

[Dave_eng]

A piece of clear plastic fuel line and a temporary gasoline container.

Do this outside as gas much more dangerous than diesel.

Hold gas container, something small and with not much liquid, at higher elevation than pump.

Crank engine and you should see gas sucked up and then run down into carb.

Dave

 

[Jim L.]

Is there a fuel pump vacuum pressure tester out there??

Maybe something like a MityVac hand tool. It has a gauge, vacuum hand pump, and a cup to trap liquid.

Could pull vacuum to see if fuel goes into and fills the filter.

Could measure vacuum at filter connection point when engine cranking.

 

[Leonidas]

Now looking for low pressure vacuum gauge to test that fuel pump.

 

[Dave_eng]

You do not have to buy anything.

Make a U tube manometer out of clear plastic.

See youtube video to see how simple it is.

https://www.youtube.com/watch?v=2P5_J5JEHTQ

You can use water in the U. The difference in the height of the water under suction is the suction in inches of water.

This is what is used by natural gas technicians who are measuring pressures around 7" of water.

Pressure of vacuum... measures the same way

Dave

 

[wgator]

You can view the FD501V service manual on line and/or download it free BY CLICKING HERE

 

[Leonidas]

I can blow air into the gas tank from the fuel line that was connected to the fuel pump intake. Drawing fuel from the tank is very hard. Will have to take tank off again and check it out. Something is pinched or clogged up still. Out of town family members require I suspend for a few days.

 

[lugbolt]

Fuel pump runs off of the camshaft.

The first thing I would do if you suspect that the push rod is not working is to remove both spark plugs and do a compression test. You are going to want to see 150 psi or greater, closer to 200 is ideal. If both cylinders are low, you likely have a broken camshaft. If that's the case, the cam GEAR (part of the cam) is broken (it is plastic) and since the camshaft doesn't turn, the fuel pump push rod won't work either. Removal of the engine is required for access. The new cam gear is also plastic so the problem will likely happen again a few years down the road. On the Kawasaki Mules, the newest revision of the camshaft has a metal gear, but you also have to replace the spur gear on the crankshaft to match the new metal gear--and it's a bit of a chore requiring disassembly of the motor to do it (pressed on).

I didn't read the original post 100% but did you replace the fuel pump already? The old pumps originally had a small hole in the pump housing that lets atmospheric air push the diaphragm, but when the diaphragm begins to leak fuel will weep out of the vent hole. Well of course the muffler is directly below the fuel pump and there's a good chance of fire. The new fuel pumps are a little different in that they have a spigot at the vent, and you're supposed to route a little hose from the spigot out along the frame and away from the muffler so that if (when) it leaks, it won't drip right on top of the muffler. I've seen a bunch of burnt up mowers from this exact issue, and if you ain't already bought a new style pump, I'd suggest doing so!

 

[Leonidas]

Final update. Purchased 2psi electric fuel pump from SUMMIT Racing. Had other issues with fuel lines that required all new fuel lines. Thanks everyone.