19 turn rules!!!!
I can't think of any way to keep stock interesting? Throw em away and run a 19 turn.
Same amount of maintenance if not less, very little if any price difference in the motors, and they're faster. I only have one stock motor and it's not exactly legal.
Leave the stock motors to the novice racers. Especially on a track the size of yours. 19 turn is even almost too slow for that track.