CV730 has me stumped

[RevB]

I have a cub cadet commercial mower with a Kohler Command CV730 on it. It starts up fine, idles decent, but when I rev it, it seems to be loading up with fuel. It struggles to rev smooth. When I engage the PTO it falls flat on its face. It starts sounding like a diesel sputtering. Parts I have replaced trying to figure it out: Stator, voltage regulator, both coils, both spark plugs, idler pulley on deck (all the rest move free), carburetor, fuel pump, fuel filter, fuel lines, and both head gaskets. I don't know where to go from here. The only thing I noticed today was that the fuel filter doesn't have much fuel in it when I was revving. Anyone here that can help? I appreciate it!

Edit: I have also pulled the flywheel to make sure the key was not sheared. It was perfectly fine. There were questionable wiring changes made before I bought the mower, but it ran great until it didn't. The previous owner had removed the ignition and replaced it with 2 toggle switches. 1 to turn power on and off and the other is a momentary start toggle.

Update* I have checked everything over once again and found that cylinder #1 is not running properly. I have checked the spark plug and coil gap and it has good looking spark. Switched plugs between the cylinders and #2 still runs hotter/better. Put water on both exhaust exits and there's a pretty big difference, cylinder #2 evaporates immediately while cylinder #1 takes a few seconds to do so. I took the valve cover off of cylinder #1 and the pushrods and valves are moving just fine, compression seems good as well. So I think I'm dealing with a small valve leak or possibly a problem with the cam. Has anyone had a similar issue? Any ideas how to test further?

Parts cannon.

 

[MParr]

How many hours does the engine have on it?
Have you done a cylinder leak down test?

 

[Will9000]

How many hours does the engine have on it?
Have you done a cylinder leak down test?

Hours unknown, the hour meter doesn't work. I haven't done a leak down test yet, but I will be in the next few days

 

[MParr]

Hours unknown, the hour meter doesn't work. I haven't done a leak down test yet, but I will be in the next few days

That's a good idea especially before you spend another dime on it.
And a compression test.
The engine may be worn out.

 

[Will9000]

That's a good idea especially before you spend another dime on it.
And a compression test.
The engine may be worn out.

That's what I'm leaning towards. Worn cam or something else that's not worth it to fix

 

[Mark H_NO]

I know you pulled the valve covers, did you adjust the valves?

 

[Will9000]

I know you pulled the valve covers, did you adjust the valves?

Yes, I have pulled the covers, but on this particular Kohler, there are no valve adjustments. It has hydraulic lifters

 

[Mark H_NO]

Ok then. Compression or leakdown test then.

 

[esemilio]

Ok then. Compression or leakdown test then.

How about checking that there is no leak at the intake manifold at cylinder 1; could be a loose bolt or break in gasket.

 

[hlw49]

Could be a loose valve seat. Burned valve or worn cam shaft. Turn the engine over by hand with the valve cover off and see if both rocker arms are opening the same.