The Bendix (trademark) device operates on centrifugal force. To get the CF you need to slam the gear into the flywheel gear, you need AMPs; like for my 90 hp 3 cylinder the number is 120. Taking ohms law and the fact that you need 10v usually across the starter (during cranking at this high amperage) to get the force needed, you basically have 2 volts available for connection losses for battery internal resistance and all connections between the two. 2v/120 amperes is 0.016 ohms which is nothing. Good battery, full charge, clean and tight connections (on the inside where the current flows) good cables, and what the other guys said about the Bendix are what it takes.
If you cleaned the Bendix, and have 10v across the starter when cranking THEN you can worry about a starter rebuild.
HTH,
Mark
