I don't know if this engine is old enough to have been derated by the
use of a thicker head gasket to compensate for poor quality fuel. So,
you may not get the 90 HP you're expecting.

If it hasn't been rebuilt yet, it's a ticking time bomb. Factor in the
cost of a rebuilt power head ($1800 - $2000) when negotiating final
price. The good news is, if it lasted this long, the previous owner
took care of it.

If it has been rebuilt, don't forget all the other original and
expensive to replace parts that were reused, i.e. the starter ($200),
alternator ($300), lower unit ($1000).

Now that OMC has changed hands, I don't know how long spare parts will
be available. Don't forget, 90 HP Evinrudes were available with the
FICHT nightmare. If it's a FICHT, that should be the deal breaker,
unless he's willing to deduct the full value of that motor from the
sale price.

John