I bought a used maxx from ebay that was missing the spur gear. It was advertised as "all it needs is replacement spur to run". I replaced the spur but noticed that when I turn the spur the wheels don't spin. I took the tranny apart and didn't notice any stripped gears either. It looks like there are some centrifigal clutches which would require more rpm than I can provide with my hand spin in order to engage. Is this accurate? Are there checks I can do by hand before starting? I am dealing with engine issues atm so it may be a couple of days before it runs.