2013 Cub Cadet LTX 1050 KW Won't Stay Running

[KountryKevin]

Problem (short version)
Tractor runs for 10 20 minutes mowing the lawn with its 3-blade 50 deck and then quits. Let it sit for 10 minutes or so and it will start again but quit again in a shorter period of time.

Problem (long version)
Bought the tractor/mower at an auction. It was not well taken care of. Caked in mud/dirt and 50" 3-blade mower full of grass. Cleaned up the tractor and mower deck (removed it, reattached it). Changed oil (10W30), new oil filter, new air filter, new spark plug, new blades, new battery. There was about half a tank of gas in it but I didn't know how old it was so I added some Stabil to it. Ran like a top. Cut my lawn twice with it. No problems.

Then the mower belt snapped. Took the deck off. Replaced belt with a new one (Cub Cadet brand made for the 50" deck). Ran great for a few minutes.

Then the mower deck threw a pulley. I think I forgot to tighten it correctly after removing it. The pulley had to be removed in order to install new belt and I just biffed on putting it back on right. Anyway, I bought a new pulley, installed it and mower cuts great again but, as mentioned above, tractor only runs for 10 - 20 minutes from cold.

I should also point out that at some point between it running great and then not, the old gas ran out and I refilled it with new gas from gas station (87 octane - not E85).

Fixes Tried (and Failed)
I thought maybe the drive belt was sticky or maybe came off one of the pulleys in such a way that it would run for a bit but then the extra friction would cause engine to overheat and stall (a reach, I know) or maybe when the mower belt snapped or threw a pulley the violence of it all broke the cooling fan under the tractor seat. Anyway, I lifted the seat and removed the battery - fan was intact I could pull the drive belt through an entire circuit - visual inspection of the belt did not reveal any fraying or undue wear. So, I'm thinking it's not the drive belt.

I thought maybe the coil was overheating so, one time after it stalled, I pulled the plug out of the cylinder (plug was wicked hot, but I got it out), grounded it to a nut, then turned the ignition - not only did it spark, but the motor started! And ran! With the spark plug a good 3 away from the hole! So, I'm thinking it's not the coil.

I thought it was the fuel flow removed fuel line, turned ignition - gas came out. Blew through the fuel line - all clear. Had a look in the gas tank and it appeared clean. So, I'm thinking it?s not the fuel flow (line, pump, tank). I read somewhere that the gas cap vent could be blocked up. Cap does not appear to have a vent so I ran it with the gas cap completely off - motor still stalled. I also thought I was getting vapor lock - the fuel line is stupidly close to the exhaust. However, there's a little bracket that holds the fuel line away from the exhaust a few inches so I am thinking it?s not vapor lock either, unless the design was flawed.

So, that?s it. I am out of ideas. Any help? Thanks!

Regards,
Kevin

 

[Bob_Bainbridge]

You can try spraying starting fluid into the air intake immediately after it quits. If it runs on the starting fluid that would indicate a fuel delivery problem. If it won't run with the starting fluid it would indicate an electrical problem such as coil, ignition switch, interlock switch etc.

Bo B.

 

[Dave M7040]

Agree with Bob B's suggestion to diagnose problem.

I suspect a failing fuel pump or cracked vacuum line which powers the fuel pump.

Kohler Fuel Pump NEW 17 HP | eBay

Dave M7040

 

[KountryKevin]

Thanks guys! I will run those tests and let you know how it comes out.

 

[KountryKevin]

OK Bob B, I did your test. Motor conked out after 15 - 20 minutes again. I sprayed starter fluid into the air intake immediately afterward and it started right up. So, it sure seems to be a fuel flow problem. I think I am going to go ahead and order a new fuel pump. I also figured I may as well get new fuel lines while I am at it. I'll let you know how it turns out (might not be until next weekend). Thanks for the help!

 

[Richard001]

Does this engine have the fuel shutoff solenoid on the carb? Could be that it is failing after it gets warmed up.

Richard

 

[KountryKevin]

Does this engine have the fuel shutoff solenoid on the carb? Could be that it is failing after it gets warmed up.

Richard

I just checked the parts manual. It does indeed have the carb solenoid. If the fuel pump/fuel lines don't do the trick, I will look there next. Thanks for the tip!

 

[KountryKevin]

Welp, it wasn't the fuel pump or fuel lines. Ordering the solenoid. We'll see if that's it?

 

[tomplum]

You could nip the plunger on the solenoid and see if that's it to expedite things.

 

[KountryKevin]

Well, 3 months later, here's an update. As noted above, I installed a new fuel pump and that wasn't the problem. I installed a new solenoid and that didn't help either. My neighbor Joe didn't like the color of my spark, so I installed new coils and wires; didn't fix it. BUT, it does run for a sustained period of time now AS LONG AS I start out with a full tank of fuel. Once the fuel gets down to 1/3rd - 1/4th full, it stalls out as before. So, I guess a cheap repair would be just to keep the fuel leve up. However, I really would like to get to the root cause and fix this thing. Any ideas? Thanks.