Looking for a new ,"used" engine.  Wondering if it is worth repairing?  I located this unit for a friend.  He talked to the owner and ok'ed the purchase.  Bought it home it started once and he drove it around the vineyard for a few minutes, shut it off, and it has not run since,  Took it to the dealer and after $2100 in trying to locate the problem, we were told the engine needed to be replaced.  We are in this over $7400 and have nothing to show for it except headaches.  Need some advice.  I can do a lot of mechanical work, if we can find parts to fix it.  The engine will have to be overhauled.  I have seen some rebuild kits for around $300, but don't know much about the quality.  Any advise appreciated.  Thanks.  Bill