starter not engaging after removing

I searched first before posting but didnt really find much relating to what im seeing so here it is. Ive had a weak starter connection for awhile and have just been bypassing the solenoid so we took off the starter and opened it and cleaned the brushes/connector thingy. Seemed to fire up more regularily after that but the issue is now it just freewheels. The gears appeared to have reengaged, as it wouldnt go in otherwise (right?) And it was turning over fine up until i did this. What could cause this? And the battery is fully charged, it seems to spin with gusto so i dont think it is relate to that (as ive seen other posts suggest). I just cant imagine what it could be. Help!

 

Pls elaborate on "weak starter connection"

 

Starter button intermittently working, needing to bypass the solenoid to start the bike about 90% of the time. When the button worked, it was fine starting but most of the time it was not working. That is what i meant by that. It was starting and running fine except for the starter button. Was going to just install a momentary switch near the solenoid but opted for taking the starter off and cleaning off the thing the brushes rub against and checking the brushes also. They could use being replaced but were not so bad, and i cleaned a fair amount of grime off the thing they connect to which seemed to help make the starter button work better at least. So it starts still just doesnt engage the motor. Sucks. Not what i expected to hae happen

 

Maybe you don't have it back together properly. There's a little slot inside the casing that the armature (I think) has to line up with when you put it back together or it won't engage. This happened to me the first time I took apart my starter. I missed the slot and it wouldn't spin when I put it back together. Maybe this will help.

 

First off, make sure it's spinning in the right direction. It's easy to get one of these starters back together so that it turns backwards.

 

The slot thing i did notice, and while assembling i wasnt confident in it so we went back and made sure it all lined up. Three times it took, so at least that part im pretty sure about. And the starter did spin, just doesnt want to engage. The spinning backwards part, that we didnt test for. How is it possible to put it back together where it spins backwards though? That doesnt even make sense to me when i think about how it came apart and went together. I will check that though but i cant even see how that is possible. Thanks for the replies thoug guys