Looking again at your picture ,I see you have the flywheel cover off .you may be able to look with a flashlight from underneath and see if the starter drive gear on the starter meshes into the flywheel when you push the foot peddle ,you would need a helper and disconnect battery and block truck so it won’t roll when underneath.BeSafe.you can also mark with chalk the flywheel and turn motor over by hand and count and inspect teeth on flywheel ,although with no grinding or noises it is probably a starter engage problem.enjoy
