2004 200 ox66 plug fouling

[rwstoney]

I have had to change the spark plugs 5 times in a year to get my motor to start. Again last night. Change the plugs and it starts right up. The motor is run no more than 4000 rpm and using Yamalube.

[boats.net]

Have the oil injection and fuel injection system checked to see if working properly. Check thermostats and cooling system, cold running engine will foul plugs. Run Ring Free in fuel to help keep engine clean. Check engine mounting height, if engine if getting sprayed with water or backwash getting into cowling engine will suck water into air silencer and will foul the bottom spark plugs.

[tsheehy]

How many hours since the oxygen density sensor was serviced?

-- Tom