My Murray Rider Lawn Mower will not start. I thought the problem was the starter selenoid so I replaced it. No Good, still won't start. When I crank the key, a loud high pitched and continuous noise is made. Is this a starter issue or spark Plug? Thanks!

Starter issue... most likely the starter drive gear... Likely plastic teeth that stripped off. Went through this with my Craftsman Lawnmower last year.

Awkward to replace... but not that expensive... and no you don't need the entire starter.

Thanks Smoothy! So I can fix this by replacing the starter?
Jeff