The flywheel spins freely when the key is turned and the spark plug is removed. When the plug is installed, the starter can barely turn the flywheel. Just bought a new plug and battery. Problem seems to be internal resistance in the motor. Motor has only 37 hours on it. Nothing runs like a Deere....
Lets start with the model number of the mower as well as the model number of the engine from the valve cover. So we can see what variation of engine you have.