I have a mtd 12.5 hp riding mower... I have done all tests on switch solenoid and by passed these and the starter mower will take off but when it engages to flywheel it seems to stop turning... the flywheel is not hard to turn therefore I'm thinking it still might be starter... the starter turns good but it takes awhile for gear to engage to flywheel... could there be a voltage problem when gears engage it does feel to be locked when engaged... help

Could be that the starter is just plain wore out.