Mower has 24 horsepower Briggs & Stratton motor. When you turn the ignition the starter seems to engage and try to spin the motor. But it only gets about an eighth of the rotation and then bounces back. You can spin the flywheel by hand but it's like the starter does not have enough power to spin it.
It has a brand new ACDelco battery with 330 CCA and the starter was replaced last season as well as the solenoid. It seemed as if the starter In solenoid are doing what they're supposed to do since they are trying to spin the motor. Any ideas?
Take the spark plug out & try again
Engine spins freely usually means a failed compression release.
Double check it is not bad wiring by hooking up the starter directly to the battery using jumper leads
Hook the starter side + first to avoid accidentially shorting out on the engine.
IF you replaced the starter with a cheapie off Amazon then better than average change the starter has failed.
a couple of years ago we were awash with really cheap "heavy duty long starters, suit Briggs & Stratton " .
These all turned out to have only 2 magnets , not 4 like a genuine one and lighter wire so all they did was use more power and burn up the wiring.
#3
Fish
Also remove the valve covers and take a peek. Things may have rattled loose and messed up your valve clearances.
