So recently, I broke the old motor on my slash. Called up Traxxas, sent me a brand new replacement for free. Thank you! Anyway, when installing I noticed the gear on the end was a 16, and the one on my old one was a 19. The 16 didn't mesh to well with my bigger gear, lot of bad rattling noise and horrible power delivery. So I mounted the 19 on my new motor, broke it in, and when I started giving it the gun, etc, I noticed that if I floored it from a stop, it would go way slower than the engine was revving. I think it catches up, but it's like theres less power being delivered.