Outdoor Power Equipment and Small Engines - kawasaki 23hp w/slow starter

After spending hours reading the post but not finding my solution I was impressed with the site so I registered and I am a newby. I hope someone can help.
I bought a used Ferris ztr with 23 hp Kawasaki engine. The engine cranks very slowly almost as if battery was nearly dead. This hampers engine starting. Things I've tried:
Replaced battery then tried a high amp car battery
Had starter checked
checked mounting fit when it was reinstalled
checked compression
checked valve clearance
pulled cam shaft and checked compression release- then replaced camshaft ( I really thought this would fix it)
other tune up but not necessarily related, checked fire, carb adjust, new fuel pump, new plugs. Some of these items made it start sooner but the starter still turns the engine slowly.

Oh, it runs great after it finally starts.

Is there possibly a higher torque starter available? I do know that the Kaw 23 in John Deere has some different parts than the one in Ferris. I checked but their starter won't fit the Ferris engine.

Thanks in advance

Well ,it looks to me like you've checked all the obvious and even not-so-obvious things. I might suggest reducing the vlave clearance on the exhaust valve a tad if it can be afforded without impairing normal operation. That's assuming ths starter is performing 100%. How was the starter checked?

Thanks,
The starter was checked at the local alternator repair shop. They might have missed something.
After finding that the cam had a compression release feature I thought replacing them was going to be the solution. The engine labors to turn over as if there was too much compression.
I was having some of the work done at the local John Deere shop. There is a local Ferris dealer but their diagnosis was "yeah, some of them do that".

Some other things come to mind to check. 1- Starter cables condition - three total, checking not only the appearance but more importantly the cable ends as well as the point where each one mates to, for corrosion. 2-Possible excessive combustion deposits presence - this will create higher compression. 3- As Cheese mentioned, excessive valve clearance especially on the valve related to the MCR (mechanical compression release). Which valve this actuates differs from model to model but should always be the valve nearest the PTO end of the crankshaft. 4- Although rather unlikely, don't overlook the starter solenoid as a possible problem area. As far as heavy-duty starters go, I'm unaware if Kawi has such a starter.

check, check and check. The valve clearance sounded like a possible cause but has been double checked.

I may be able to "borrow" a new starter just to see if the starter test was not accurate and that the starter could be the problem.

I'm not familliar with this unit. You should be able to do a "starter draw" test on the starter. The max current draw will be posted in service manuals. I have had many Golf Cart starters come from the local rebuild shop as O.K. But they draw too much when under the load of cranking the engine!!

Thanks for all the help! We found the problem! It was the starter after all even thought the test showed it was OK. The new starter really spins the engine. The folks at the John Deere dealership are letting the starter/alternator shop know their testing is not sufficient.
I suspect that the old starter was not turning the engine fast enough for the compression release on the cam shaft to operate.

Thanks again

Perfect!! Glad to here You got it going again, Roger

Great! Glad you got it. I had a suspicion it was the starter for some reason. Looks like everyone else here thought so too.

Thanks for the update!