Mercury 40 4 cylinder problems

[2mate]

Hi there,


Im having a few problems with my 1991 mercury 40 4 cylinder oil injection outboard. I rebuild it last month and have been waiting for the weather to warm up before starting it. Its had new oil seals,o rings,carb rebuild and a crank case re sealed. I went to fire it up today and water appears to be getting into the bottom cylinder? I didn't take apart the water jackets during the rebuild but have just taken them off and there is a milky substance on the exhaust plate. I thought the oil seals and gaskets would have sorted this problem, could the water be getting in from the water jacket gaskets?
Cheers

 

[oldman570]

Re: Mercury 40 4 cylinder problems

The exhaust cover plate and the divider plate can allow water to enter the piston if the gaskets are bad or the inner plate is cracked or pinholded from the heat and any crossion that has happened over time. Would be best to check it out before any real damage is done to the motor. JMO
Oldman570