I have had the same problem recently, I believe. With mine, if you kick it over too fast from the start the teeth won't catch, it just grinds and there is no force on the motor. I personally believe it is the spring wearing out. To remedy this, I spec'd out a new spring that I am about to test as my motor comes back together. I cut the spring to the same OEM length dimension but ordered a spring wire that would require more force to compress it than the OEM. This change should make the racheting gears engage easier and quicker than the worn out oem one. I will be mentioning this and commenting on it in my "little engine that could to beast mode" thread in the next coming weeks. I get tired of having to be so ginger with the kicker to get the gear to engage. And they ratchet gears aren't even wore out. They show minute to no wear on them.