2005 Sportsman HO work

Hello all, I have been a member for some years but after moving to Tenn. and selling all my machines except one, and leaving that one in Maine, I am back to learn some more. Just got it down here and I have been perusing the Sportsman forum for info on suspensions, transmissions, and decompression. This might be long winded.
I rebuilt the engine after the OW burned it up just like the build that is ongoing by another member. I didn’t go crazy with with the frame and all as it was only 5 or 6 years old when I got it. I did a leak down test on the valves and put them back in, replacing the crank, rod, piston and timing chain and gears.
From the get go, the engine has MUCH compression, I have not tested it. But you cannot start it with the pull cord. Is this normal? I think not. I took it to a local dealer when in Maine last June and had them put on a new magneto and carb kit and asked them to evaluate my rebuild. IS it running correctly? Is it sounding right? (it is very…..rappy….knocky?) I was worried about the timing as it is a bear to set it.
What can anyone tell me about proper operation of the decompressor device?
I have the service manual and this is my winter project to get everything else up to speed. Bushings, service the transmission, any thing I can find.

Any tips and acvice would be appreciated.

Kevin

Sorry, the dealer told me it ran fine. I put 250 miles on it the last 2 weeks in Maine. I should have mentioned that the starter, which is new, wont spin it over like I am used to. It comes up on a compression stroke and stops, you have to work the key to start it.