I have seen this many times.
what happens is, you press start> the starter relay is energized and connects power to the solenoid >the solenoid pulls in which extends the pinion gear on the starter jackshaft to engage the clutch flywheel> after the pinion gear engages the flywheel on the clutch, the solenoid closes a contact to apply battery power directly to the starter motor> as the starter motor starts to spin but does not start the engine> you release the start button but the pinion is bound up on the flywheel and does not retract, holding the contact in the solenoid closed to keep the starter motor energized. the only way to stop the starter is to disconnect a battery cable.
- the engine does not start because battery voltage is too low for the ignition module to make spark.
- when this happens, the cause is typically a old, bad battery.
- just because you have a new battery doesn't mean it's any good. I recommend HD and Interstate only. most others are made in China and, frankly, not worth the box they come in.
- another cause can be worn, old cables, but I see you've replaced those.
- another cause can be a bad starter. there are companies that sell sell poorly re-manufactured starters as new starters. depending on where you got your new starter, it may be the problem.
- and a major cause of jackshaft binding is an over torqued jackshaft bolt. the HD manual is incorrect. the proper torque on that bolt is 36 in-lb. just 3 ft-lb. snug. the tab on the retaining washer is what keeps the bolt from coming unscrewed. if you believe you may have over-torqued the jackshaft bolt, try loosening it up. if the tab on the retaining washer is broken off, you should replace it. (the tab broke off on my bike, so I bent the entire side of the washer up against a flat on the bolt......it works.)
- the only other causes of binding in the starter drive on that model are the jackshaft bushing in the primary chaincase and the bearing in the primary cover. if the battery, cables and starter are NOT the problem, you should consider replacing the jackshaft, primary bushing and bearing in the cover.
let m know if you need more help.