Hi guys new to The Forum not new to bikes. I have a 92 Sportster 883 to 1200 conversion, not that it should matter (they both use the same starter).
I'm having an issue with the starter not making a full rotation. The Jack shaft comes out and engages but cannot turn the bike over. If i pull the plugs she'll spin all day long.
I have multiples of everything- starter, Breakers, relay, batteries, start switches, and no matter what i swap i get the same result, starter engages but acts like it doesn't have the nuts to turn all the way over.
so far I've checked the ground to battery and frame, replaced positive cable from Battery to starter with another that I had. Swap the relay, swap Breakers, swap starter, brand new battery that load tests out and has almost 500 cranking amps, both stator and rectifier test out fine.
I'm obviously missing something and was hoping you kind gentlemen could maybe steer me back to the right path cause I'm lost.

 

After testing my ignition breaker and other Breakers, I found that they were showing ground. After some screwing around I found that once the headlight is unplugged all the breakers are no longer grounded. Bike still does not start though

 

a) repair your ground issues
b) how much voltage is coming from your starter relay to the solendoid? if the voltage drop on that wire is too much,,,,,
take a wire straight from battery positive(with fully charged, known good battery, and touch it to the terminal(solenoid) on the starter and see if it spins,,,,if so the issue is on your solenoid circuit wiring. A compression test might be usefull as when this conversion is done with certain pistons the comp can go up quite a bit, but the starter should still be able to handle it. try this test and report back and we can see what the next step is.
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