Motor self starting issue
 

HH 45t sport

wont run unless you help it start spinning.

replaced teh brushes, that didnt help, cut the comm that didnt help. The motor spins with lots of tq when you give it a little help to start but if you just power it on, it wont spin.

Ideas?

i had the same problem , it was a broken wire on the comm. i soldered it up and all was well.

think I found it... wasnt a broken wire but a loose wire. The wires go into little pressure clamps on the comm and of them was a little loose. I tightened it with some pliers and now it seems to work well.

Thanks for pointing me in the right direction.

Sounds like an armature stall, either a broken wire or short in the windings. If you can't see it externally on the armature, the only "fix" is to replace the arm or motor.