Weird Issue - Engine Bogs & Stalls When Engaging Mower

[RLS0812]

Please read this post before copy-pasting something you found on Google.

I have a Husqvarna YT42XLS with a Kohler KT735-3011 engine. It run and drives very smooth, however last season it would bog down and die whenever I engaged the mower.
I have to attempt to engage the mower many many times before it will decide to stop bogging down.
I am able to easily turn the mower belt with my fingers, and after I removed the belt, I was able to easily turn each blade. I fired up the mower without the mower belt on, and it bogged down and died again when I engaged.

Before I start tearing the engine down ( potentially wasting my time ), does anyone know what the issue likely may be?
Thank you in advance for any advice

 

[bertsmobile1]

Put your finger on the governor arm and try to accelerate the engine
If it does the same thing you have a problem with the main jet .
Put a volt meter across the battery using some long wires and see if you get a significant voltage drop when you turn the blades on ( electrical problem )
Unplug the PTO clutch and see if the problem goes away ( bad clutch ? )
Put an electrical load on the PTO wires ( old headlamp 60W or higher works really well ) then turn the PTO on and see if it does the same thing ( bad charging circuit )
Charge the battery overnight with a charger then see if the problem takes longer to start happening ( bad charging circuit )

That should keep you from Google for a while
And if you start to dictate how people respond who are trying to assist you don't be surprised if no one bothers

 

[RLS0812]

That should keep you from Google for a while
And if you start to dictate how people respond who are trying to assist you don't be surprised if no one bothers

.
I do apologize for that. I've been researching this issue for several months now, and been turning up the same unhelpful information dozens of times for the issue I am having.

I'll start running the tests you have mentioned as soon as I can get some time to play with the mower.

 

[Gord Baker]

Allow the engine to warm up first may help, or have it running at higher RPM when engaging.

 

[mike73]

That does sound odd. Do make sure you start blades at full throttle if you're not already, I think that is specifically stated in some instruction manuals.

My initial thought was that if it was a twin cylinder engine, it might have a dead coil on one cylinder- I've had this happen and it doesn't sound much different unless you have a trained ear, but it lacks enough power to mow. Try unplugging one spark plug at a time, it can run on one, so if you unplug one and it dies, you know that cylinder was doing all the work and the opposite coil is probably bad.

Less likely, but it could be an electrical fault that is causing a short when blades are turned on (if electric clutch). I say this is less likely because it would probably blow a fuse or cause random stalling while you're mowing also, not just when starting blades. However, the idea that it does it when starting clutch even without belt on is what makes me think of the electrical problems. Had a customer's mower stall out in the middle of their yard, they couldn't get it to work. I lifted the hood and it started right up for me. Once I drove it, I realized the headlight wires were shorting out and making it stall.

Engine could also bog if oil level is too high, air filter is dirty, etc.

 

[jshep1102]

Seat safety switch bad and it thinks that you have been ejected so it grounds the coils?

 

[artemjemmy]

Please read this post before copy-pasting something you found on Google.

I have a Husqvarna YT42XLS with a Kohler KT735-3011 engine. It run and drives very smooth, however last season it would bog down and die whenever I engaged the mower.
I have to attempt to engage the mower many many times before it will decide to stop bogging down.
I am able to easily turn the mower belt with my fingers, and after I removed the belt, I was able to easily turn each blade. I fired up the mower without the mower belt on, and it bogged down and died again when I engaged.

Before I start tearing the engine down ( potentially wasting my time ), does anyone know what the issue likely may be?
Thank you in advance for any advice

So you are saying it dies even with the belt off, whenever you engage the PTO? This sounds like a safety switch problem. A wiring diagram that should apply to your mower is attached. To check if it is a safety switch problem, I would find that junction connector that goes to the reverse switch and the seat switch and disconnect it. If the blades engage fine with this connector unplugged, you know that it is grounding out through either the reverse switch or the seat switch. Just as another check, what does the engine do when you turn the key to the "reverse override" position (one spot clockwise from OFF) and try to engage the blades?

 

[billypumper]

Had the same thing happened to me on a JD LX 279 replaced the battery, problem solved.

 

[Joed756]

Seat safety switch bad and it thinks that you have been ejected so it grounds the coils?

You copied and pasted that.

 

[jshep1102]

You copied and pasted that.

No, I typed it laying in bed. Did it sound like a good possible cause or a crappy one. Just wondering if I should be insulted or pleased with your accusation? I'm thinking insulted but thanks for reading my reply.