Cratsman Mower Won't Start, Flywheel Stuck!!!

Good morning everyone. I am new to the forum and need some help. I have a craftsman riding mower model #917270620 with a Briggs & Stratton 15.5 hp OHV model # 28N707. In the fall I was using it and it was running good. Stopped to refuel and when I went to restart, it would not start. Got a clicking sound. Waited until now to try and get it going again. Have replaced the ignition switch and solenoid. Starter is getting 12 volts when attempting to crank. Flywheel is stuck will only turn about 1/2 inch clockwise and counterclockwise before it stops and sounds like it's contacting some metal. I would appreciate any help with trying to diagnose and fix this problem.
Thanks.

First easiest, look at valve gear including pushrod (s). Are they there? Possible debris jamming timing gear on crank. Clicking while running or solenoid clicking?

:welcome:

Three things come to mind
1) engine seized
2) loose or broken magnet under the fly wheel.
3) stuck valve

If it just feels like the piston is stuck so you are just taking up the slack when you try & turn it back & forth then piston seized is No 1 in the suspect list.
If you can turn it a little in each direction and it makes a hard klunk sound then a loose magnet is the No 1 suspect
If it turns about 2/3 a revolution and stops with a squeeky sound then stuck valve is No 1 suspect.

Undo the nut/ bolt on the flywheel and pull it off

Solenoid clicking when trying to start. This is my first repair, so I don't know much about engines. Where are the valve gears and crank located?

Start with the easy things first.
Take the engine cover off it is held on by 4 bolts.
You may also need to remove the fuel pump which is held on by 2 bolts, just undo it and push it aside.
The flywheel is held on by a big nut or bolt .
If you have a rattle gun and a big puller then use that if not undo the nut/bot two turns put a pry bar under the flywheel and put a lot of weight on the bar then hit the end of the nut/bolt hard with the biggest hammer you can lay your hands on.
The shock will pop the flywheel off the tapper you then undo the nut/bolt and the flywheel will lever off.

Start here because this is the least amount of dissasembly required to check off a potential cause and if it is not the problem it will need to come off in any case.

Next remove the carburettor and check that the two butterflys ( round brass discs ) are both there and the tiny bolts that hold them to the shaft.
The throttle one ( nearest the engine ) can come loose and enter the engine and jamb the valve, howevet this generally stops the engine at a specifie spot so it will turn backwards & forewards till the stuck valve stops the engine turning which is not what you are describing.

If it was not the flywheel remove the 4 bolts that hold on the rocker cover which is at the front and has OHV pressed or cast into it.
When it comes off ( might be glued on with silastic as well ) you should see two rods coming up out of the engine ( pushrods ) and they push agains a small lever ( rocker arm ) that pushes down onto a valve.
When not being pushed up by the cam they should be a loose rattly fit, that you can not pull off.
If you can the pushrod has jumped off the followers on the cam shaft and you might be looking at a complete dissasembly of the engine.
So get this bit done and let us know exactly what you see and smell.

Also check the oil, feel it between your fingers and smell it.
It should feel a bit thicker & smoother than cooking oil and smell slightly sweet. read the oil level off the dip stick. let us know exactly what you find.