chances are, starter's one-way bearing is bad. if it '' catches '' here and there ?, then yes, the one-way bearing is bad. anytime it starts from the pull starter, but not the electric starter ?, this tells me your one-way starter bearing is bad. it at the back of the motor, behind the flywheel. in order to replace it, you must remove the back engine cover that holds the stator, you will need a rear cover gasket, and a flywheel puller tool to pop the flywheel off, bearing is sitting on, and behind the backside of the flywheel.