I have tried out quite a few motors, and found one that has just the right amount of power for the setup I have.
I found that with stronger motors, it muscles the needles too much.. to little, and it is well, too weak.
Anyways, there have been some complaints with the T-Tech cartriges and my machines.
The spring puts just a little more resistance on that what my motor likes to have.

I have found a solution though!
putting an extra rubber band on the rubber band screw mounts, and having it go over the armature bar will counter balance the spring tension and help it even run smoother.

Hope this helps for anyone with the T-Tech setup.

Also, my motors are rated for up to 10 volts, and nominal voltage range is 6.
So, bumping up a volt or two isn't going to destroy the motor.

Thanks.