well i managed to hit a pretty large rock that i couldnt see of course w/my toon sat night & took out the lower unit on my 70 force. the prop didnt even break, it took the the shaft right out w/the prop & everything!!!what to do now????i can get a jihnson 1oo hp for about 300$, that's what i'm thinking of doing now either that or i know a guy that has a 55hp johnson that's running on his boat now & is willing to sell it for 295$--will that be big enuff for a 21ft toon???????