My John Deer ztrak f620 Commercial Mower Still Wont Start

I found out that I had a bad PTO switch. I replaced it. Now it turns over but it wont start. I sprayed starting fluid and it runs for a few seconds then it stops. I replaced the fuel pump, replaced the spark plugs and replaced the worn out fuel lines. It turns over but won't start. Its like it is not getting gasoline to the carburetor. The gasoline in the tank is good. What can it be?

Check the fuel shutoff switch on the bottom of the carb. Listen close to it when you turn the key on. It should click. If it does then you have a clogged carb. If it dont then it is a electrical issue. Maybe bad fuel shutoff switch, bad ignition, bad safety switch on mower somewhere.

I had a mobile mechanic take a look at my John Deer F620. He replaced the carburetor. He claims that there was water in my gas tank. The old carb was corroded. Where the engine would turn over, now it just clicks. It seems like the starter is having a tough time turning the engine over. I don't understand. It would run start and run when I sprayed ether in the carb. Now it won't even turn over. Is it possible that the engine is now seized?

Take the plugs out & try turning it over.
Be carefull because fuel could spurt out & singed eyebrows are only fahsionable if you are under 30.

If it cranks fine plugs out but won't crank plugs in then the decompressor is cactuus.
Not all engines have them so please post the full engine numbers stamped into the engine so those with access to the Briggs power portal can find out the exact specs of your engine.