Just wanted to no what the compression should be on a polaris deisel 455

Test the compression using a compression tester.
My guess a valve is stuck closed.
A compression test will show this.

Anything around 100 would be acceptable. 85 is about the minimum that an engine will run on.

Yes there is - and it gets stuck at times. It does on mine anyway. Work up in garage and see if problem goes away.

If you have spark at the right time, fuel, air.... you might try a spray of staring fluid. I would then check the compression. If it is too low it will not start.

Low compression, trash in carb,or valves

With the decompressor active, nominal is 85 - 90 psi. At 62 psi, you have a top end problem. Try dumping a bit of oil in the cylinder and re-test. If the pressure rises, you have a ring seal problem. That sounds like an top end rebuild.

ok 4 things could be the problem,
check to see if you have spark. if you have spark then spray some starting fluid into the carburetor or air box. if it does not start then check the compression, if the compression is good, and you have spark then check the camshaft. these have been known to eat the exhaust lobe of the camshaft right off. that is where i would start.

sounds like you have a hole in piston check compression with a compression gauge, should be about 125 psi

no oil sensor or shut down ---if carb ok would change spark plug

Polaris uses an automatic decompression that sits in the exhaust cam. There is not an external lever as there is on older Kawasaki's and dirtbikes. What seems to be the issue as to why you're looking for a compression release?