Hey Jim,
could be your "diseling" problem is a symptom of poor fuel. Too low of
an octane rating can cause dieseling, also carbon buildup in the heads
can cause pre-ignition or dieseling. If I were you, I would pull the
plugs and look for excessive carbon buildup and fill up with the best
grade of fuel you can obtain.


Capt. Frank

jim wrote:

Hello,

Anyone know if I could have damaged my 2001 mercruiser 3.0 running at
WOT for over an hour?

Afterwards, when I turned of my engine, it dieseled. Tried it a couple
times and it keeps dieseling. Ill try super unleaded next time out but
concerned if any permanent damage could have been done especially since
it was in salt. Never dieseled before. Only about 20hrs on it....sigh.

TIA!