2003 Heritage Starter Problems

have you tested it with a booster pack with the negative clamp directly on the engine and the positive clamp directly on the bendix

That does not sound good. I suggest you get it to a dealer before you do any additional damage.

is your engine turning over, if it is, pull your spark plugs and clean them. this happens on my 98 Heritage Softail Classic. It sounds funny but from long warm ups with choke pulled they get carbon build up and this keeps the plug from firing. If your motor is not turning over then you Bendix gear is out on your starter.

Check timing belt first , check starter also .

are you sure you got a good solenoid?souds like it's not kicking the starter bendix out for the start.if it hums that means it's turning right? it has to be the solenoid not kicking the starter bendix into the flywheel to start the engine.i would try another solenoid. thank you for choosing fixya.com

Replace the "Bendix" unit on the starter shaft in the primary. It's basically a one-way bearing designed to lock up when turned one way and to freewheel when turned the other. When the starter turns the "Bendix" it locks up but when the engine starts, the Bendix turns the same way but faster. This make it reverse directions in relationship to the starter shaft. When they go bad, they either don't lock up at all or the "jump out" once started turning the engine over.

Do not use a cheap Bendix replacement (made in China). You'll be back in there again in six months if it lasts that long. I like the Accel units made in the U.S.A. Clamp the shaft in a vise with "soft jaws" on it and take the nut off the end of the shaft. It has left handed threads.

Good Luck
Steve

The starter bendix is not engaging properly the bendix pushes the starter gear into the flywheel gear when the starter spools up, it may need minor lubrication.
It sounds like the engine is not getting fuel as it should, the main jet may be restricted from varnish if she stumbles under a load especially if the plug tips are white after running for 1/2 an hour.
Remove the float bowl and clean the jet, make sure the fuel is still good, gas that smells like a library is more like varnish and less like fuel.

The starter isn't kicking out the jackshaft or bendix and engaging the flywheel or starter sprocket it sounds like.