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I have Kolher Command 25hp in a Cub Cadet LT1050. I have an unusual problem and I'll add as much detail as I can here.

- When I bought the mower it had about 185 hours on it. I noticed the air/oil separator was cracked, didn稚 seem to impact function of the unit. Did have some occasional backfiring when shutting down, other than that Worked good all year.
- Next year (stored inside for a winter) changed oil, spark plugs, air filter, after a while about ｽ through the mowing season, the mower would act like it was running out of gas, looping and surging, after mowing for about an hour. I thought this was a fuel filter issue because the fuel filter was mostly empty when it happened. To troubleshoot the issue I致e done the following:
o Replaced Fuel/Oil separator, (valve cover breather) and gasket all air tight now
o Cleaned Carburetor, used Kolher carb rebuild kit, new gaskets and float etc. (Seemed to help overall running, but issue recurred)
o Replaced Pulse Fuel Pump, Air filter, Spark plugs
o Checked Fuel Solenoid Shut off Operation (seems to work good)
o Re-routed and replaced some of the fuel lines (seemed to help a little, no clue why)
o Relocated Fuel filter to under gas tank so it stays full. Replaced Fuel filter 3x, no real change.
o Ran with gas cap off, gas cap vent clear
o Ran multiple tanks of gas- not a fuel age issue

- So with all of this the only things I致e learned are, if I disconnect the fuel lines (like to change a filter, pump, or replace line) the situation seems to get better for at least an hour or 2 of cutting. I have no idea why though. Sometime when it starts to Surge and act like its out of gas, a little choke will keep it going for a few extra minutes, but it will eventually just die. I致e checked the bowl on the carb after it dies and it seems like there isn稚 enough fuel in it, but there is still enough in there that would make me think it should run (about 10-20 ml?). The carb is NOT hot when this issue happens, and it doesn稚 seem like the engine is over-heating. The engine usually starts and runs good prior to the 妬ssue although it does seem lately like it痴 lacking power for a 25 HP engine. I致e tried to look for intake or exhaust leaks, but don稚 have the proper tools to perform a leak down test. Any suggestions would be helpful. What is causing me a headache is that the issue will go away for a little while and then randomly return.

Hey there - WELCOME to LMF! :smile:

I moved your thread to the Small Engine & Mower Repair Forum. You'll get a better response there. :thumbsup:

Had a similar problem with my 25 HP, have you checked at the gas tank if there is a filter screen and if so us it OK, on my Walker it was collapsed.

Wm.Harold said:

Had a similar problem with my 25 HP, have you checked at the gas tank if there is a filter screen and if so us it OK, on my Walker it was collapsed.

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Yeah i've focused mainly on a fuel obstruction to this point. There isn't a fuel screen i can see in the tank, but i know that fuel will freely and easily flow from the fuel line, and the fuel pump will flows good when disconnected from the carb to a bucket.

It sure sounds like you are close to the problem.

I'd guess that the fuel is being consumed just a tad faster than it is being delivered to the carb, resulting in it getting leaner and eventually stalling.

It could be one thing, or there could be several contributing factors - all adding up to restrict fuel flow just enough to cause this.

I'm interested to hear what you find, good luck!
Bruce.

Make sure your fuel filter is made for a tractor with a fuel pump. If the microns are to fine you will starve the tractor of fuel. I had this happen on one I had to watch the fuel filter for some time before it ran out of gas. You could replace the fuel line and dont put a filter on it and run it first to see if your problem goes away.

Rob

My 1050 is doing the exact same thing. Did you find a solution?

You mentioned the backfire at some point. The fuel solenoid on the bottom of the carb. were put on these engines to keep it from backfiring when shutting down. They are supposed to shut off and then retract shortly after to allow fuel back in the jets. These are known for problems, mainly that gum builds up on the plunger and doesn't allow it to retract fully. This can cause the starving for fuel. The fact that it runs for a while means it is almost surely a fuel problem. The only other thing I can think of is if the coil malfunctioned when it heated up. This is really rare. Be sure to let us know what happens

Try a new set of plugs. I had some NGK act up when the mower gets hot.

Rob

Thanks for the advice guys-

Here's the update

I decided to rule out carb and solenoid problems by tossing some money into this pos tractor. I bought a brand new carb and solenoid (got a good deal on Ebay) threw it on with some new spark plugs replaced the fuel filter and all the fuel lines. The mower ran real good for a while. It still has the same issue though however but it's not nearly as bad (I get about 45 min between stalls with a 5-10 min recovery).

The fact that this helped the issue, but didn't resolve it has got me even more stumped about this-

I thought about over-heating, but that doesn't seem to be an issue- it doesn't seem to be overly hot and the plugs didn't look burnt (if anything they looked a little rich running with black build up most likely from my use of choke to keep it running while dying???)

Do you think a clogged crankcase breather could cause this? Is there any electrical issues?

Get a spark tester and run your mower until it dies then check if you still have spark. It is a cheep way to rule out the coil. Where in MI are you located?

Rob

I'm just west of Lansing.

I've tried to check the spark a little- I've pulled the wires when it's running (to see if a loss of spark would replicate the issue) and the engine bogs down but doesn't stall out like when it's having the issue. However at this point i'm not rulling anything out, i'm going to get a spark tester or maybe use an extra plug to do a quick test. If it was spark or engine related i just don't understand how a new carb would make the problem better.

What do you guys think about these "theories"
1. A clogged up crackcase breather causing a pressure build up? OR
2. A minor headgasket leak causing exhaust gases to blow back into the intake system (only rears it's head when the engine gets warmed up??)

I dont think is a head gasket problem. You can check the CC breather while its running to see if its plugged. I am not sure about the new carb making it a little better. Check the spark and get back to us and lets go from there.
Rob

try running with gas cap off....if its vent is plugged...it could do a similar thing

I have a CV16 Kohler Twin doing the same thing. Acts like its being starved of gas after running 15 min. Leave it off a few minutes and it runs fine again.

I replaced the fuel pump but did not help. Checked hoses all seemed ok.

1. Could be blocked oil separator causing the fuel pump not to work well
2. Blocked gas tank vent. Will check this out
3. Loose Dipstick cap - not sure if this would lower the crankcase pressure enough to cause fuel pump not to work.
4. Fuel filter blocked. checking this too.
5. Gasket leak.

Since mine runs great I might just hook up an electric fuel pump and not worry about the pulse type fuel pump.

I'll post back if i figure it out.

I was having some issues with my Toro 266H (16Hp V twin Kohler command)

It would die after around 20 minutes of driving. I would let it sit for 5 minutes and it would run great again. It seemed like it was starving for fuel.

Funny thing was my wife could mow all day and it would run fine for her.

I bought a new Fuel pump for it but it did not do any good. Then i thought maybe the fuel line could be cracked.

Long story short. It was due to the fuel line running between the gas tank and the frame. I had drained the tank in the spring and the line must have slid under the fuel tank when I put it back together.

I weigh 230 and mife wife is 115Lbs. She was not heavy enough to crush the gas line so the mower ran fine. I was just heavy enough to compress the line after like 20 min if mowing.

Anyway I took it apart and moved the fuel line in the proper place.

I also have a new filter and fuel pump.

It runs great now. My wife thinks i did it to get out of mowing

Starting cutting grass this season and I'm having the same problem you were having last year.Did you ever figure out what the problem was.Somebody said to try replacing the fuel shut off solenoid. Any ideas would be helpfull.Thanks

Sorry not to add an update in so long-

Unfortunately I never really figured this issue out. However I've narrowed it down to something with the air intake/fuel supply.

If I run the mower on about half power it seems to be less of an issue (cub cadet salesman said to run at full throttle but the 25 hp engine cuts fine at half throttle)

Also to really make this weird- I noticed that if I spray the air filter with carb cleaner the thing runs great. I'm embarrassed to admit that I keep a can of carb cleaner on my tractor and quick spray the filter if it starts acting up. (i know it's not safe, and i know it's a "duct tape" fix- that's why i'm embarrassed)

I'm going to pick up a new air filter tomorrow and see what difference that makes. I did notice my mower is missing the oil soaked pre-filter that is in the book for this model- I'm wondering if too much air flow has caused this issue and soaking the filter somehow helps, but this doesn't really add up to me. I'll post more when i know if i don't set myself on fire while mowing.

Have you changed the pulse line going to the pump and where it is attached to the engine. You could have a crack at the point where the pulse line meets the block which opens when it gets warm. I would also check valve clearance. If it is to close heat expansion may cause the valves to same open to long. Also, I don't know the spec of you engine, may have hydraulic litters are pumping up.

Rivets said:

Have you changed the pulse line going to the pump and where it is attached to the engine. You could have a crack at the point where the pulse line meets the block which opens when it gets warm. I would also check valve clearance. If it is to close heat expansion may cause the valves to same open to long. Also, I don't know the spec of you engine, may have hydraulic litters are pumping up.

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Pulse is good- I've replaced all the lines, clamps, and checked for cracks. I event checked fuel pump flow by pulling off the outlet and turning the engine over- it spits a strong flow of fuel.

As far as the heat expansion - I would imagine that would be worse on hot days opposed to cool days- I mowed when it was 50 out yesterday and it was the same as 90 degree day. I'm not sure how to check the valve clearance- is it difficult- and it is adjustable?

Please poetry's de and spec numbers for your engine this will help us help you with the next step.

Fingers are getting too big. I meant please post model and spec numbers

I have a club cadet tractor that keeps stalling and with a little carb spray it gets by a few more minutes
I have replaced gas lines and carb. parts are costly and work and time involved is crazy this has been a ungoing problem for 2 years now the two mechanics i have working on this tractor can't figure it out.. the tractor will run for 15 mins then quit running I really have not one else to ask , but seeing all this response it looks like that club cadets are known for this kind of problem
if anyone has any ideas or has this happened and they fixed the problem please let me know

thanks you so much.

sukey said:

Thanks for the advice guys-

Here's the update

I decided to rule out carb and solenoid problems by tossing some money into this pos tractor. I bought a brand new carb and solenoid (got a good deal on Ebay) threw it on with some new spark plugs replaced the fuel filter and all the fuel lines. The mower ran real good for a while. It still has the same issue though however but it's not nearly as bad (I get about 45 min between stalls with a 5-10 min recovery).

The fact that this helped the issue, but didn't resolve it has got me even more stumped about this-

I thought about over-heating, but that doesn't seem to be an issue- it doesn't seem to be overly hot and the plugs didn't look burnt (if anything they looked a little rich running with black build up most likely from my use of choke to keep it running while dying???)

Do you think a clogged crankcase breather could cause this? Is there any electrical issues?

Click to expand...

I think i would replace the fuel pump

My LT 1050 has all the symptoms discussed in this post. Has anyone been able to find the fix to the problem? I watched with the hood open this past weekend while it sputtered and died, the fuel filter was full of gas but yet seemed like it was starving for fuel. This was with the choke pulled all the way out.

I have replaced the fuel filter and on Saturday removed the fuel tank to verify nothing was stopping up the outlet to the fuel line.

I would focus my attention of the fuel tank vent. When it starts to sputter, loosen the fuel cap and see if that revives it.

Thanks, I will go back double check but I thought I had the cap loose the last time when it died. I will post my results back to the page with any updates.

I pulled the gas tank off again today to make sure there was not anything stopping up the drain from the tank as well as to make sure there was no trash in there. I made sure nothing was pinching the gas line before putting the fender and seat cover back on the tractor. I replaced the plugs for good measure as well as gave it a shot of carburetor cleaner in the air breather. The gas cap seemed to be clean, I did remove some grass from one of the vents but all others were clear. I filled the tank with fresh ethanol free gas and fired up the mower! It ran well ...... for about 10 minutes and back to the same sputtering and starving for fuel. I pulled the choke out and got a maybe another 30 seconds out of it before it quit running. After this it would crank but not keep running.

Any thoughts on what to try would be appreciated.:confused2:

Did you loosen the fuel cap when it started sputtering?

Lawn mower diagnosis 101.
Get an in line spark tester or better still a colortune and fit it
Get a can of starter fluid.
Remove air filter, give the mower a shot and try to start it.
If it starts but will only continue running is you keep giving it short shots of starter fluid the you have a fuel problem

If the colortune / spark tester does not flash or stops flashing before the engine starts to die, you have an ignition problem.

If you have a fuel problem the remove the float chamber and replace the cut off solenoid with a bolt/.
Engine runs OK the the solenoid or power supply to it is bad.

If the solenoid checks out OK the get a temporary fuel tank ( pinch it off your push mower )
Hook it directly to your carb and hold it as high as you can above the mower to give you the best head pressure.
Runs OK then you have a fuel pump / fuel line problem
No difference then you have a carb / manifold / valve problem.

Hook up the original fuel line again , start the engine & keep it running with short shots of starter fluid.
With a TRIGGER bottle of water/ Wd40 etc liberally spray all around the intake manifold.
Engine speed changes = air leak

Finally check the governor by starting the engine then hold the throttle open by moving the governor lever with your finger.
Works fine if you hold the lever open = governor problem

wildbird said:

I think i would replace the fuel pump

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The fuel pump was the culprit. I had it replaced and it runs like a champ again!