X126 model won't turn over

[Graham ford]

I have a x126 model ride on mower only 4 years old, went to start it didn't turn over thought it was a bad battery , purchase a new one and the same thing happened the starter kicks in but won't turn over the engine, have taken the spark plug out and the engine seams to fly over with no problems but put the plug back in it won't turn
I can turn the engine over by hand using the pulley at the bottom it has no problems
Anyone can help please

 

[SeniorCitizen]

I often use jumper cables from battery directly to starter to eliminate some of the failure possibilities . If that fails to crank the engine , move on to having the old battery load tested . You can still try the jumper cables to determine if there is a weak component in the system that's causing the almost cranking situation .

 

[StarTech]

Either your valves are way out adjustment or the Briggs camshaft ACR have failed. The IPL idicates you have a Briggs 310000 series and the ACR (automatic compression release) on these are bad to fail.