Courage 20 Won't Crank

Hello,
I have a 6 year old Husqvarna lawn tractor with a Kohler Courage 20 engine. Sometime last year it started getting hard to start, now it's to the point where the starter will spin the flywheel 1 revolution and then stop. If you hold the key to the crank position it will eventually do another revolution then stop & continue on that cycle. After reading through forums I learned of the automatic compression release and that it can be affected by the valves being out of spec. So far I have adjusted the valves (2 or 3 times for good measure), changed the battery & starter solenoid, checked the starter and cleaned all wiring connections. When I pull the spark plug out it will crank till the battery's dead. I'm dead set that this is a compression issue, but the valve lash is not correcting the issue. Is there any where else that anyone can point me? I'm sure that the cam lobe for the ACR could be worn or something else could be wrong internally, I just find it hard to believe that is the case being that it is only 6 years old with a little over 200 hours (if that) on it.

Thanks in advance!