What is the problem if my mercury outboard motor is getting a milky substance on the spark plug i pulled the w

Question

What is the problem if my mercury outboard motor is getting a milky substance on the spark plug i pulled the w

Answer 1

do a compression test this will tell the tale. A merc comp should be 100-175 psi on all cylinders and not more than 25 psi difference between all cylinders.

Answer 2

then check the head gasket

Answer 3

It is water and oil mixed. seldom from fuel,  Check gaskets for leak.

Answer 4

Head gasket most likely.

Answer 5

Milky stuff on the plugs is almost always an indication of water mixing in with the gas/oil.  I would toss the gas (or at least check the tank for water) and get a new water filter for the fuel system.