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I have owned this 62" mower for 20 years. Suddenly, the fuel filter is empty and the mower shuts down - as if I turned the key off. Let it set and the fuel filter {Vacuum} refills to 50 to 75% with the mower off. Restart and it may run for 30 minutes or 2 or 3 hours (it decides). Here is what I have done: Replaced fuel pump (twice), replaced fuel filter, replaced all fuel lines including the rubber grommets on each saddle tank (the pick up hose in the tanks are new), blew out the 90 degree elbows on each tank, new tank selector switch, new breather valve (flapper) & gasket, rebuilt carb and new gaskets, verified governor settings, gas tank cap vents are clear, tanks are clean, new spark plugs, new coils and the compression test were 123 & 125 PSI. I don't think I left anything out. Mower starts great. It mows great (62" deck). You start mowing with a fuel filter 50 to 75% full. 15 minutes later, you see NO visible gas in the filter.....after which it will shut down at any time. It may last 15 minutes....1 hour or 2 to 3 hours. My yard takes 5.5 hours to complete under normal conditions. What am I missing??? I have re-inspected all the new fuel lines, been through 2 new fuel pumps, rechecked the gaskets on the manifold and carb, re-inspected the rebuilt carb, fittings are tight, hoses were new and feel snug. Any suggestions?

What fuel filter are you using? And how did you verify the vents are working properly?

Scrubcadet10 said:

What fuel filter are you using? And how did you verify the vents are working properly?

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The filter was purchased at our areas go-to equipment dealer. I don't recall the exact make. I used a wire and air hose to verify the vent holes were open. I have also loosened the tank cap, as I was mowing, to see if it would increase the gas flow in the filter - which it did not.

Shuts down as if you turn off the key doesn't sound like fuel issue to me. Loss of fuel issue normally will spit and sputter a few seconds before actually dying. Issue to me thinks more of a loss of spark issue. Does this engine have the oil pressure switch which could be faulting out and causing the engine to shutdown.

Compression is below the 160 minimum that Kohler suggest, which may not be a cause but could be a symptom of something else.

ILENGINE said:

Shuts down as if you turn off the key doesn't sound like fuel issue to me. Loss of fuel issue normally will spit and sputter a few seconds before actually dying. Issue to me thinks more of a loss of spark issue. Does this engine have the oil pressure switch which could be faulting out and causing the engine to shutdown.

Compression is below the 160 minimum that Kohler suggest, which may not be a cause but could be a symptom of something else.

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I will have to see if it has an "oil pressure switch"? The shutdown takes about 3 seconds...a single or duel very quick shudder then nothing. But, I am drawn back to the empty fuel filter - 15 minutes of sitting and I have enough gas in the filter to restart. Would the oil pressure switch impact fuel delivery? Fir the record, I have noted that the lipstick tube is loose and easily pulls out from the block if you lift it. Would that impact the vacuum that operates the fuel pump??

Robert Boudreau said:

been through 2 new fuel pumps

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Where did you get these from? Scamazon or Fleabay? OEM parts????

From a reputable mower/tractor/small equipment dealer.

Rig up an aux fuel tank that is HIGHER than the carb. Just to confirm lack of fuel is the issue. Mow with it a while. Many a time fuel filters can look dry and the engine still runs.

Robert Boudreau said:

re-inspected the rebuilt carb

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Did you pressure test the carb needle/seat at 7psi for 30 minutes? Does the needle allow fuel into the bowl area?

Robert Boudreau said:

From a reputable mower/tractor/small equipment dealer.

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So the new fuel pumps are not working? Guessing these are OEM Kohler parts?

I removed the fuel line going to the carb and placed it in a container. I then turned the key. The pump was pumping gas thru the line into the container. So, the pump is working.

Really need the spec number of the engine. About 100 different CH22 listed. Also the equipment make and model would not hurt.

Still can be defective fuel pumps. Last year I know for sure Oregon had a bunch bad aftermarket pumps. They would fail at any time. Matter of fact I had three of left from last year. The one installed this year failed after an hour of use. Would not self prime or quit intermediately. Appears to had been defective pump check valves so I just trash the other two.

Rotary also had a problem with them last year but in house quality control caught that one. Their current pumps have passed their in house quality control.

Hi Robert,

When it shuts down have you checked for an overheating ignition switch? Is the backside of the switch accessible? What about the after-fire fuel solenoid on the bottom of the bowl getting too hot and failing? Be careful checking for any hot wires or the solenoid because they can easily burn your fingers.

The solenoid connector is bad about spreading the pins and create strange shut down problems.

We've been heavily focused on the fuel system, but a hot electrical circuit can create similar problems. Even a main fuse holder and the fuse often get hot, especially with age.

By the way, a fuel filter being full is not a reliable sign of a fuel starvation. I have seen many run at full throttle with a near empty fuel filter. It is a matter of how much fuel the engine is demanding under load that makes the difference.

That brings us to the carburetor. It would be good idea to pull the bowl and remove the float and needle for inspection, then blow through the fuel inlet in case any debris is stuck in there. I have found sediment and debris caught in them that would act like a shutoff valve.

Hope this helps you

CH22s-66522 on Yazoo with 62" deck. Both fuel pumps I purchased were Briggs and Stratton. Someone just suggested a possible Oil Pressure Switch malfunction. I looked on the mower and located what I believe to be the switch (to the right of the drain plug). Not sure how to test the switch (other than replacing it)....or, if it's malfunction would shut the mower down (one way or another). But, at this stage, I will try about anything with my capabilities.

Auto Doc's said:

Hi Robert,

When it shuts down have you checked for an overheating ignition switch? Is the backside of the switch accessible? What about the after-fire fuel solenoid on the bottom of the bowl getting too hot and failing? Be careful checking for any hot wires or the solenoid because they can easily burn your fingers.

The solenoid connector is bad about spreading the pins and create strange shut down problems.

We've been heavily focused on the fuel system, but a hot electrical circuit can create similar problems. Even a main fuse holder and the fuse often get hot, especially with age.

By the way, a fuel filter being full is not a reliable sign of a fuel starvation. I have seen many run at full throttle with a near empty fuel filter. It is a matter of how much fuel the engine is demanding under load that makes the difference.

That brings us to the carburetor. It would be good idea to pull the bowl and remove the float and needle for inspection, then blow through the fuel inlet in case any debris is stuck in there. I have found sediment and debris caught in them that would act like a shutoff valve.

Hope this helps you

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I assume you are referring to the key ignition switch? If so, this is accessible for a fairly easy inspection. I will check it out in the morning, as I have not inspected it. As for the after-fire solenoid, I clipped the pin completely off, which did not resolve the issue. I had the carb apart since rebuilding it last week. Clean as can be. As far as the main fuse, I will have to look that one up....not sure where that's located - but I will check on it.

Robert Boudreau said:

I assume you are referring to the key ignition switch? If so, this is accessible for a fairly easy inspection. I will check it out in the morning, as I have not inspected it. As for the after-fire solenoid, I clipped the pin completely off, which did not resolve the issue. I had the carb apart since rebuilding it last week. Clean as can be. As far as the main fuse, I will have to look that one up....not sure where that's located - but I will check on it.

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Yes, I am referring to the keyed ignition switch.

slomo said:

Where did you get these from? Scamazon or Fleabay? OEM parts????

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Pumps were made by Briggs & Stratton.

slomo said:

So the new fuel pumps are not working? Guessing these are OEM Kohler parts?

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I pulled the engine covers and cleaned the engine & fins before changing the ignition coils 2 weeks ago.

Robert Boudreau said:

I removed the fuel line going to the carb and placed it in a container. I then turned the key. The pump was pumping gas thru the line into the container. So, the pump is working.

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Now pull the carb bowl off. Turn the key on. Carb needle should allow fuel into the bowl area. Get a drip pan ready. Make sure plenty of gas runs out the carb needle and seat.

slomo said:

Now pull the carb bowl off. Turn the key on. Carb needle should allow fuel into the bowl area. Get a drip pan ready. Make sure plenty of gas runs out the carb needle and seat.

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The carb bowl is built into the bottom of the carb (it's not detachable). To get to the bowl, you have to remove the top half of the carb to expose the bowl - which would thus still be attached to the engine. This the original OEM carb - I just rebuilt it.

Robert Boudreau said:

The carb bowl is built into the bottom of the carb (it's not detachable). To get to the bowl, you have to remove the top half of the carb to expose the bowl - which would thus still be attached to the engine. This the original OEM carb - I just rebuilt it.

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Forgot to mention that after rebuilding the carb and still having the issue, I took off the carb and went through it again. Everything was as clean as could be. No dirt or blockages. Engine started right up - which surprised me, considering I had just emptied the carb to inspect it. I mowed 2.5 hours running better than it had in the past year. Then, it shut down....with just a slight hesitation. 15 minutes later, I had gas back in the filter and restarted the mower - mowing again for about an hour (repeat story). The engine shroud was removed and cleaned when I replaced the coils about 2 weeks ago.

Status report: I have finished all the work, cleaned the engine, checked the wiring, fuses and cleaned all wiring connections. Started the mower (I noticed a little surging - though not consistent) and mowed for an hour or so. The mower was running good. Then it shut down. I checked the ignition switch/wiring. It was cool. I noticed a small amount of white smoke - not much. With the mower outside under a noon sun, the lighting was good. To late to be brief.....but, what I discovered was a leak down around the breather cover cover. However, it was not leaking from the breather gasket. To me, it looked like it was a possible combination of oil and gas. I say that because the fluid was neither clear or dark (like dirty oil). Again, the fluid (that I could see) was on the top/backside of the engine (as in above the coils).
My guess (I am not a mechanic) is that the engine is running hot and shutting down. I believe this accounts for the lack of visible gas in the fuel filter - once the engine was started (especially since I had previously eliminated all other possible fuel issues).
With this said, I am wondering if I have a head gasket leak??? Would that account for a possible vacuum leak (accounting for the lack of gas issue)???

Robert Boudreau said:

I removed the fuel line going to the carb and placed it in a container. I then turned the key. The pump was pumping gas thru the line into the container. So, the pump is working.

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Like this video? I would replace all three fuel lines. Bet one of yours has a crack in it.

Robert Boudreau said:

replaced all fuel lines including the rubber grommets on each saddle tank

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Meaning the incoming fuel line, impulse hose off the block and the output line to the carb inlet right? 3 hoses on the fuel pump.

From what you are saying, you have a fuel delivery issue. Your filter is empty and engine shuts down.

If you've cleaned the tank and outlet, installed new hoses and filter and still have no gas, you have missed something. Gas cap opened to check for a non vent condition which will cause no fuel flow from the tank.

Did you pressure test the carb?

Hi Robert B.,

There is a pulse type fuel pump that has the 2 fuel lines (supply and carburetor) and then a 3rd line for the crank case pulses to operate the pump. Check that line and make sure it has not split or coming apart so that it is barely hanging on.

This is not an engine head gasket issue. That will not come and go like you are describing.

I rule out the ignition coils also, because they do not just quick working at the same time.

Since you've spent countless hours on this and replaced or checked numerous parts without success, I'd try a new carb. That is assuming you tried a new temp aux tank and did replace all 3 fuel lines.

Scrubcadet10 said:

What fuel filter are you using? And how did you verify the vents are working properly?

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Have you cleaned out the fuel tank? I had an old John Deere 318 that I picked up cheap that did the same thing. Turned out there was a huge amount of sludge in the bottom of the tank that was restricting fuel flow. Cleaned out the tank and that took care of that problem. May not be your problem but could be worthwhile to check it out.

Anti-fire solenoid? I know you rebuilt carb, but was the solenoid replaced? Run with spark testers on it. Run with kill wire TEMPORARLY disconnected to verify safety switches.

Robert,

I had the identical problem with a Simplicitith an 18 HP Briggs Vanguard. I tried everything and so did the dealer. I finally solved it by selling the mower. Sorry I don't have better news...

Al

You did not (at least what I read) the make of the mower. I will state what I have found on Gravely Z turns. There is a steel fitting that pushes thru a bushining into the fuel tank. On the other end of that fitting is a flexible hose that is pushed onto and special clamped onto the fitting. As the hoses age the deteriorate and crack and some have even fallen off. So if you have this type of tank i9t may be a palace to check. Note there is a fine screen strainer on the other end of the hose.

Sorry, but I didn't read all the posts... But my theory of small engine repair - or any engine repair - is, check the simple things first. You said you did check the fuel venting... But I'd run it with no fuel cap and see if it still dies. It does sound like you're getting a vacuum in the fuel system.

Some on this forum will disagree, but if Op doesn't want to pay for an oem carb, he can always try amazon and ebay for about $15. If it works, then bingo, if it doesn't you have lost little.
I know Chinesium carbs are controversial on this site, but 20 out of the last 20 I tried worked fine. Others have had a different experience, true enough. But if price is a big concern for Op, then this is merely an option for OP, and no one else!

For the most part, the Chinese carbs have been fine for the last several years. I used to buy the cheapest listing, had issues in the past. Now I buy one that is say $10-15 bucks more than the cheapest listing. No issues since. I still go through each one looking for deficiencies. Float heigh set proper and so on.

I went back through most of the posts, and this is pointing toward the fuel tank having to be removed emptied, then flushed out and left sit to dry for a couple of days. While it is drying, go back through the lines, elbows and pick up tubes.

You are chasing a globule of trash and bad fuel likely mixed with water. This stuff moves at random at the bottom of the fuel tank and will drive you crazy.

The other possibility is a cracked plastic pickup tube. Think of a bent/cracked defective straw when you are trying to drink from a soda cup. Cracks in plastic tubing expand with time and heat on riders.