2005 LT1050 engine cutting out

rd400racer · #1 03-05-2026, 07:00 AM

My 1050 has been a dependable workhorse for over 20 years. I do regular maintenance and every 5 years take it to a reputable shop for a "going over". At the final cut of fall, my engine starting cutting out...almost like there was water in the gas or something akin to that. I removed the deck and started it up, ran perfectly. Put the deck back on, hit the PTO and it started cutting out again. That makes absolutely no sense. Is there some kind of sensor or a part I'm missing? Cutting season is coming soon and I hate to be without.

evhevh · #2 03-05-2026, 07:33 AM

Here are a couple of things to try.

1. With the deck removed did you happen to try the PTO? That would tell you if the issue is electrically related to the PTO (I doubt it).

2. It sounds like the load is making the engine act up. Is it a two cylinder engine? If so, I would check and make sure both cylinder's are firing. It sounds like the load from the PTO/Deck is straining the engine with only one cylinder running. There are multiple ways to test if both cylinders are running. (i.e. bad spark plug, lost a coil, etc.)

ironman · #3 03-05-2026, 09:19 AM

Quote:

Originally Posted by rd400racer

My 1050 has been a dependable workhorse for over 20 years. I do regular maintenance and every 5 years take it to a reputable shop for a "going over". At the final cut of fall, my engine starting cutting out...almost like there was water in the gas or something akin to that. I removed the deck and started it up, ran perfectly. Put the deck back on, hit the PTO and it started cutting out again. That makes absolutely no sense. Is there some kind of sensor or a part I'm missing? Cutting season is coming soon and I hate to be without.

When you say "cutting out", do you mean the engine continues to run but misfires and runs badly,
or do you mean the engine acts like it has a strain on it and wants to die or dies immediately.

rd400racer · #4 03-05-2026, 11:02 AM

Quote:

Originally Posted by evhevh

Here are a couple of things to try.

1. With the deck removed did you happen to try the PTO? That would tell you if the issue is electrically related to the PTO (I doubt it).

2. It sounds like the load is making the engine act up. Is it a two cylinder engine? If so, I would check and make sure both cylinder's are firing. It sounds like the load from the PTO/Deck is straining the engine with only one cylinder running. There are multiple ways to test if both cylinders are running. (i.e. bad spark plug, lost a coil, etc.)

Quote:

Originally Posted by ironman

When you say "cutting out", do you mean the engine continues to run but misfires and runs badly,
or do you mean the engine acts like it has a strain on it and wants to die or dies immediately.

Yes, when I ran without the deck on and engaged the PTO, it ran fine. it's the 2 cylinder Kohler Courage.

And to answer the second question, it misfires and runs badly, but only with the deck attached and PTO engaged.

Totally weird, huh? Hooking the deck up and engaging the PTO should be no different than no deck and PTO engaged. That's why I'm stumped.

evhevh · #5 03-05-2026, 05:00 PM

Quote:

Originally Posted by rd400racer

Yes, when I ran without the deck on and engaged the PTO, it ran fine. it's the 2 cylinder Kohler Courage.

And to answer the second question, it misfires and runs badly, but only with the deck attached and PTO engaged.

Totally weird, huh? Hooking the deck up and engaging the PTO should be no different than no deck and PTO engaged. That's why I'm stumped.

Based on what you say, I would definitely check into this - 2. It sounds like the load is making the engine act up. Is it a two cylinder engine? If so, I would check and make sure both cylinder's are firing. It sounds like the load from the PTO/Deck is straining the engine with only one cylinder running. There are multiple ways to test if both cylinders are running. (i.e. bad spark plug, lost a coil, etc.)

evhevh · #6 03-05-2026, 07:52 PM

The other thing to check is to make sure everything moves freely on the deck (spindles, pulleys, etc.). If one or more is froze up, that could be putting a huge load on the engine resulting in what you are experiencing.

rd400racer · #7 03-06-2026, 08:24 AM

Quote:

Originally Posted by evhevh

Based on what you say, I would definitely check into this - 2. It sounds like the load is making the engine act up. Is it a two cylinder engine? If so, I would check and make sure both cylinder's are firing. It sounds like the load from the PTO/Deck is straining the engine with only one cylinder running. There are multiple ways to test if both cylinders are running. (i.e. bad spark plug, lost a coil, etc.)

That's an excellent idea and makes sense, thanks very much for that diagnoses.

Billy-O · #8 03-06-2026, 09:57 AM

I would also check to see if deck is operating freely.