I simply don't buy used engines if I don't know the person I am buying from, or the history of that engine. The reason is simply that one lean run can totally ruin an engine. If an engines is dramatically lower than the retail cost there is usually a reason, most of the time the seller is trying to get rid of a piece of junk. And you can't go with how the engine "looks" on the outside. Some time in a crockpot filled with anti-freeze can make an engine look brand new, but it can still be a ruined engine. I know that there are going to be people that disagree with me here, and I do understand that they may have found great engines for a bargain, but in my mind it's just not worth the risk. I'd rather buy a new engine and know for certain the condition it's in.

Just my 2¢ worth

Ken