Vessel: 1997 330 Sundancer Engines: 7.4 L Mercruiser MPI inboards (V drives) Issue: STD engine intermittently will produce a noise that sounds almost like it has lost a cylinder or two while on plane. Usually in rough water not smooth water conditions. Performance doesn't really change. Whenever this noise happens I then come off plane and will smell fuel in the exhaust. There is no evidence of fuel in the bilge/engine compartment. Saturday when this happened I waited about 2 hrs before starting the engine again and white/blue smoke was produced momentarily out the exhaust after start up. Could I be loosing a cylinder or do you think this is something else? Recent preventative maintenance: New spark plugs/cap/rotor. Refinished props. New fuel filter/water sep. Recently hooked up scan tool and no codes show up. Timing, temperature and everything else checks out A-OK. Any help here would be great.