Kohler KS 595 No Start

[jsp_333 293]

I told my neighbour I'd take a look at his cub cadet before he had to sell it as a no start.

So here's is what I've determined so far 

 

Kohler KS595 (5400 series, 541cc, ~2020/2021), Cub Cadet LT46, sat since 2022, no-start

	•	Spark confirmed: inline tester, plug installed under compression, strong/consistent flash while cranking
	•	Compression: 170 psi (healthy for this engine)
	•	Ether sprayed directly into cylinder at TDC compression stroke (valves closed) — still won’t fire
	•	Ignition module air gap checked, in spec (~0.010”)
        •       Battery removed;  Jumper cables from 2025 Sierra to battery leads.
        •       Tiny little original 12v battery sits in alcove under the seat 
        •	No history of impact/tampering — sat parked since owner couldn’t get it running approx 2021
	•	Ruling out: carb issues (ether bypasses carb entirely), weak battery/cranking speed (tested off truck battery, strong consistent crank)

 

Anybody have any other ideas or did I miss something obvious.

Cheers.

[953 nut 67,468]

Kohler Command engines are somewhat prone to have sheared flywheel keys that will allow the ignition to occur at the wrong time. 

 

 

[TT-(Moderator) 1,170]

Plugged exhaust?

[jsp_333 293]

Plugged exhaust?  Like with a mouse nest built over the winter?  I'll have a look. Thx.

As for sheared flywheel key that's where I was going next but don't have the correct Kohler puller so that means a trip to the shop which I was trying to avoid.

But at this point everything else is pretty much exhausted except for a critter home.

Just went out and looked at the tractor.   Muffler and exhaust are underneath the front end about 3" off the ground.   Ideal spot for a critter. 

I'm Going to  put a shop vac up to the exhaust pipe and see what comes out..

Never would've thought of that. Cheers.

[Bill D 2,997]

Did you check for spark?  Could have an activated safety switch that is cutting the ignition out.

[953 nut 67,468]

21 hours ago, jsp_333 said:

Spark confirmed: inline tester, plug installed under compression, strong/consistent flash while cranking

 

16 minutes ago, Bill D said:

Did you check for spark?  Could have an activated safety switch that is cutting the ignition out.

Yes he did but is it occurring at the proper time?

[jsp_333 293]

42 minutes ago, 953 nut said:

 

Yes he did but is it occurring at the proper time?

  Speaks to flywheel key I suppose.  I'm going to examine the exhaust system right now because this is really bugging me.

 

So there is nothing living or dead in the muffler.  Happened to have a shop vac attachment that made a good seal on the muffler.

Even released the muffler from exhaust port and had suction from the shop vac.   So back to flywheel key.

Edited Saturday at 06:09 PM by jsp_333
updating information

[jsp_333 293]

Examined the flywheel key today... Nuthin.  It looked like it was supposed to.  In place and aligned.