STARTER MOTOR DRAGS

Bike is an 83 KZ75L3. Starter motor was dragging so i bought a rebuild kit. SURELY this would fix it.... WRONG. Housing was full of carbon dust when i opened it up so everything got a good scrubbing with simple green, carb spray and lots of compressed air. Put the new bushings in and the new plate with the brushes. Fresh grease in the planetary gears too. Tested it and it spun with lots of torque so i installed it. Acted exactly the same. And to note it gets even more doggish when the engines hot. So what gives here?? Is it the motor or something else tightening up after the engines hot??
Its a new battery and I've checked all the cable ends. Another thought was a massive voltage drop going through the solenoid. Is that possible??
 

Can you explain what you mean by "dragging" (testing off the motor doesn't really prove anything as there is no load on it)
PS: if you look at my fault finding guide (link in my signature) there is a test plan for starter circuits

Yeah i know off the bike is meaningless. Poiint off the bike was just to see if it spun after my work. By dragging im mean slow.. wha wha wha instead of a faster vigorous turning over. Sounds weak as crap.
Your link goes to ERROR 404

Not sure why wookie's link is not working but here is the doc on the filebase. Keep in mind you have to be logged on to access the filebase. I do encourage you to pull it down and read  it as I find it very useful.    kzrider.com/filebase-alias?view=download...8:general-electrical

I have also found the info posted here  kzrider.com/forum/2-engine/621566-650-75...compatability#911518 to also be of interest. It came from Mike Nixon's site but the page now indicates it is being updated.