Murray riding mower, 12.5hp 40" deck - I do not have a model number, don't know where to look for one at on the mower.
I have a riding lawnmower that belonged to my MIL before she passed. It had been sitting for over a year without cranking. Last time it was used, everything ran fine with it.
I drained all gas out, put fresh in. Changed filter. Charged battery. She fired right up, no issues.
Put it in gear, and nothing. Forward or reverse - doesn't matter. Will not even attempt to move. Checked belt and it appears fine. All the linkage seems to work like it should, everything moves when the lever is moved.
When left in gear with mower off, I can roll the mower like it was in neutral.