When you rebuilt the starter did you cut the stuff between the contacts on the armature to a bit below the contacts. If not the brushes may not touch the contacts. Also did you test the starter before you installed it?
On the bench use jumper cables from a know good battery. Hook the ground to starter body, touch hot to the stud.
If it's on the bike Use the jumper cables and good battery, hook ground to good ground on bike. I use a front peg mount nut. Put a large screwdriver in the hot clamp. use the screwdriver as a probe. Reach under the bike and touch the stud. If the starter spins the starter is ok, if not pull the starter and check things out.
If it spins go up to the starter relay, touch the screwdriver to the stud on the cable to the starter. Does the starter spin? If so cable to starter is good.
Now remove the cables from the battery. hook one red clamp to the stud where the starter cable hooks on, touch the other red clamp to the other stud, if your bikes battery is ok, and the cables from the battery to relay and ground are ok the starter should spin.
If it does it may be the start button wiring. On the relay is two small wires, with the key and kill switch in the run positions the red/white wire should have battery voltage on it. If so unhook the blue/white wire and ground it, this should spin the starter, if no voltage ore low voltage on the red/white wire you need to trace it back to where the voltage gets lost.
If it spins you, hook the b/w wire back up. Take the handle bar switch off the bars. With the switch open Check for voltage on the blue/white wire, again should be battery voltage. If you have voltage jump the b/w to ground, this should spin the starter.
If it does you need to remove the push button and clean up the connections.
At this point the pushbutton has two different ground paths, Early bikes the button grounded to the bars then through the bars to risers, on the bottom of one of the risers was a black wire that ran around to one of the top tree clamp bolts, then through the top tree, steering stem, bearings to the frame, back to battery.
On the later bikes the switch grounds to the bars, through the bars to left side switch housing to a black wire down into headlight bucket where it hooked into the harness ground. A better ground than earlier bikes.
On either system the contact in the housings should be clean and touch clean bare metal. If you swapped the stock bars for black bars you need to clean off the black where the housing contacts touch the bars.
Leo
Im missing something here. I have a starter that won't react at all. It worked a couple times then nothing. I did all the usual stuff even rebuilt it. I did the car battery thing, but squat! 
