Kohler SV730-0011

Does the starter work (starter gear thrusts out and spins) when disconnected from the engine?
Is there no movement of the engine, or just a little?
How about noises? Gears grinding (failure of starter to engage with flywheel), thunk and engine stops hard (internal parts broken, like connecting rod), starter straining (starter engages, but can't budge the engine)?
Can you turn the engine by hand, for instance, by putting a ratchet to the crankshaft?
I can't say I understand why the flywheel bolt is out. Is the flywheel loose and spinning?
How did you measure compression if you can't crank the engine?
 

Can the stater turn the engine when the spark plugs are out?

The repair manual says your motor has a compression release mechanism. You stated "no compression release". Do you mean that the mechanism is not releasing, or that there is no such mechanism on your unit?
 
Even if the compression were not being released by the mechanism, the motor would crank a little, that is, until it built up compression, so maybe 1/4 of a turn. But you're saying it's not cranking at all, right?
 
And the starter thrusts out the starter gear, and engages but gets nowhere? Am I correct in my understanding?
 
At this point, I would increase the battery power to see what happens. For instance, use jumpers from your car to the starter battery, and try cranking.
 
I'm afraid I'm not understanding your situation properly. Please go over whatever you think I'm missing.

My apologies. From what I was able to re-search there is no compression release on the unit/engine. It does crank about a quarter turn and builds-up compression and won’t turn over.

And I hate to say this but the engine is not a SV 820 but a sv730-0011!. Im so Sorry!

With all that's been checked, I'd put $ on the starter itself being worn out / needing replacement.
 
It may still spin over with no load, but loaded-Not...
 
 

It's all the same for SV730 as for SV820. It's the same service manual for both, so I'm pretty sure it has compression release. But even if it does, and even if it's broke so it doesn't release, which I doubt, the starter should still crank the engine, just not as well. You should get a few revolutions of the motor, where you would hear it struggling against the compression as the cylinder moves up, and then speed up as the cylinder moves down.
 
Regardless of whether the battery and starter are new, just like SRTsFZ6, I would put my money on one of them being weak. You need to come up with an experiment which disproves our hunch. All diagnosis is basically a set of experiments to disprove a line of thought. You've proven that there is no internal blockage by cranking the engine without plugs. You've also proven, by the same experiment, that the trouble is not the solenoid nor is it that the starter gear doesn't engage. You haven't yet proven that the starter performs under load nor that the battery performs under load.
 
For the starter, like I previously suggested, try supplementing the available battery power by attaching jumper cables from your car, and then cranking. If the motor now cranks, you've proven that the starter is not the problem, and you've implicated the battery.
 
Are you sure the battery is charged? Take it to another similar (2 cylinder) motor and see how it works there. Or, maybe you have a battery tester, one of those boxes with a heater element to give the battery a heavy load?
 
The fact that a part is new doesn't mean it's good. Ask any car mechanic who uses non-OEM parts.
 
Make sure you torque up the flywheel nut before you start the engine.