This is a very early Checkpoint modified motor based on the Igarashi teardown. The basic Igarashi motor actually was a closed endbell motor with bushings, so converting this into a full blown modified motor was a lot of work. As you can see from the pictures the front of the can and the endbell were machined for accepting ball bearings. Also small screws were used for securing the endbell to the can, after adding some timing advance. For improved heat transfere the can also got a powder coating similar to the “black wrinkle” used at the Platinum series motors later.
Beside the typical rewinding, epoxying and balancing work, the armature also got grinding a flat spot at the shaft for using pinions with setscrews instead of the usual press-on type.
This motor don´t use a Checkpoint sticker, maybe because it´s a very early one maybe because it´s a factory motor. At the endbell you can see a color code, we think this was used as code for different winds, not found at their modified production motors.
Modified motors like this were made by Big Jim Greenemeyer from 1978, after he left slot car racing and started making RC motors instead. At the very first World Championships 1/12 scale in 1982, Frank Killam finished 2nd place on the podium at the modified class using a Checkpoint Modified motor.