Kohler Courage XT-7 Ariens Walkbehind Stalling

[12gaMakeOver]

So, as stated, I have been trying to solve a stalling issue with a Kohler Courage XT-7 Ariens Walkbehind. It pull starts easily, runs fairly quietly, has tons of power, drive engages fine, and mows well. However, after about 5-10 minutes worth of operation, it'll stall. Seems to be happening only once the mower is up to temperature. This mower has almost no time on it. I checked the gas tank for debris (clean), checked the air filter(clean), checked the oil (topped up and clean), checked the spark plug (proper gap and good burn sign), and checked the spark (strong). This one's got me scratching my head. The owner said that he believes the problem started after his wife nailed a rock. The mower doesn't wobble or vibrate while running and the blade doesn't shows signs of a big hit. I figured, if she hit a rock hard enough to cause a problem, the blade would probably be bent, which it's not. Any thoughts?

 

[EngineMan]

This is out of a Kohler Manual on a Courage but I don't have one on the XT-7

Engine Starts But Does Not Keep Running

1. Vent in fuel cap restricted.
2. Dirt or water in the fuel system.
3. Faulty choke or throttle controls.
4. Loose wires or connections that short the kill
terminal of ignition module to ground.
5. Faulty carburetor.
6. Faulty cylinder head gasket.

It could also be (after it nailed a rock) Loose wires or connections that intermittently short the kill terminal of ignition module to ground.

But head gasket and valve's would also come into the problem you have. someone am sure will come in and post a different answer.

 

[Rivets]

I would check for a partially sheared flywheel key.

 

[ILENGINE]

I have seen about 10 cases where the control cable isn't pulling the brake off far enough to press the kill button to start the mower. normally the mower won't start, but could be a case where the contact is intermittent.

 

[DJ660]

How long does it have to sit before it restarts? Maybe Ignition coil on its way out. Vent in fuel cap.

 

[DaveTN]

Sounds to me like it could be the valves getting out of adjustment as it warms up.
Runs fine cold and as it warms up to a "point" and after that it lugs down and loses
power etc. I'd pull the valve covers and check the gaps. I've also seen this a few
times where the engine will start cold and as it warms up, it starts to lose power and
lug down eventually to the point where the engine seizes up. Let it sit for 30 minutes
or more, then start it up and the same thing. Wound up being an upper crank bushing
worn and binding up due to lack of lubrication. That's a long shot on it..but check the
valves first. It'll start and run on low valve clearances, but when the metal gets hot and
expands, then you lose valve clearance and the valves won't seat and you get no power,
with lugging down etc. Good Luck! :thumbsup: