having difficulty starting 1 year old tractor... for the spring,

General info:
I have the select series x300 lawn tractor/mower
live in north east so it is sitting in cold shed
had fuel stabilizer in tractor with 1/4 filled tank in shed
battery is charged (trickle charger)
I put some new fuel in, but only a little just in case I need work on fuel line etc.. so it is 1/4 to 1/3 rd filled
I changed fuel filter still no luck
when I turn key I hear fast tapping noise and the motor seems to crank(spin of fan?)

it just does not turn over

the only thing I have not changed other than filling fuel tank to top, is I did not change spark plugs but they are only 1 year old.

Any suggestions before I call and more importantly have to pay the John Deere people to come look at it.

Thank you