Leaderboard

I am surprised the starter uses an automotive style solenoid operated pre-engagement type drive. Most modern bikes and such have constant mesh starter drives with one-way clutches somewhere between the starter and the crankshaft--the starter can turn the engine but the engine cannot turn the starter. Nonetheless, from what you describe it's obvious there is some connection/component in the starter switching circuit that is not delivering sufficient power to pull in the starter solenoid and engage the drive pinion or electrical contacts to power the motor--that's progress. Now completely disassemble the starter switching circuity wiring, clean all connections, and examine all components and wiring. If the starter itself is not the problem than it has to be a problem in either the high current feed to the starter or the control circuit. It's a "ground up" restoration of the starter wiring...