Originally Posted by
marcos graveyar
The motor is cleaned with Wurth brake cleaner, the com cleaned and bushings reoiled every other race.
Because you can't skim the comm on a sealed can motor, the contact between the brush and the comm will still deteriorate over time even with regular cleaning (I've actually stopped cleaning my sealed can motors, seem to go faster dirty!). There is an argument that motor cleaner pulls the natural lubricants out of the brushes.
It may be coincidence that both the motors you tried are at the end of their life, or it may be the Spektrum/Savox combo. I'm firmly in the "Spektrum is junk" camp and I would never let it near my cars (not a fan of Savox either, too inefficient). Sanwa is probably the best bet nowadays although I'm sticking with Futaba as it has yet to let me down in about 20 years of racing.