The other day I drove my OS .46 FX into a gravel road under full throttle inverted.. (widn got me on take off...lol) but anyway, the motor was full of rocks, the pipe ripped off and just general gashes from the impact. I took the motor apart and cleaned it out. It turned over fine before, but wanted to be safe. i was glad I did take it apart, there were rocks in the crankcase that were seated while turning it slow, but would have made a mess had I fired it up. Just better to be safe than sorry and is also a good time to check out how the piston wear is.