engine damage

Question
We hit a sandbar last night. It's a mercruiser 470 '78 i/o. The outdrive hit the ground hard. The motor kept running until I was sure that is what happened. I down throttled to see if we were still on it, then shut down. Once clear we tried to start it, it grinded really bad, then made kind of a zinging noise and wouldn't start. I dont think the prop spun loose like they are supposed to. Can you give me a list of the problems that I could be facing from best to worst? I can not put any more money into the boat other than fixing it myself. Thanks.

Answer
Hi Steve...Thank you for selecting the undersigned to reply to your question.

Did you see an oil slick at the stern of the boat after the collision? Did You check the gear housing of the lower unit for damage? Was the prop damaged and to what extent? Did the engine overheat? Did your power tilt/trim still function properly?

Although I'm not a mechanic, the "grinding" symptom suggests bearings may have seized or you've fractured a prop or drive shaft. The fresh water intake may have drawn in sand, which can affect the impeller and of course other parts of the cooling system. Once you've hauled the boat out and made a thorough inspection, chances are you may not have to speculate on the damage, as it will be visible. Hopefully you a friend that is a mechanic and will be able to help you trouble-shoot the problem(s).

Safe Boating
Ron