If you 78K hours run time without a starter Overhaul you need one. You should be able to go into the "service test" menu and check each individual contactor. If the starter has gone to "open" transition (the transition resister are no longer in the starter configuration, make sure either it stays online or leave it off. This type of operation will cause bearing damage if not addressed. See if the coils are getting the 120 volt signal and the delay is in the contactor pulling in. I have done this with 120 volt clip light on all 4 coils. If the transition contactor is working it will only be a blink or 1 second at the most. Also are you sure the screw is 100% unloaded ? good luck- GEO