I have a 1985 40hp Mercury outboard 2 stroke. I noticed that I have a small amount of water coming out of the spark plugs. (Primarily the bottom one) The motor misfires if I run it for awhile out on the water. I took the spark plugs out and they are dark/burnt looking. I ran the motor at the house with the bottom spark plug out and there is water that shoots out when I have the water hose on, but when I turn the water off the water stops shooting out.. Could anyone please tell me what seals/gaskets could cause this and what should I do, and is even worth fixing?
thank you
Water in cylinder
Moderators: bman, Chalk, Tom Keels
Re: Water in cylinder
More than likely you have a blown head gasket.
I don't remember just how an older 40 is set up. If there is a cooling plate on the head you'll have to remove it to get the head off. If this is a saltwater motor you'll probably have a very difficult time getting the bolts out without them breaking. Once the head is off check for damage to the block, piston, and head. Make sure the head isn't warped by checking it with a good straight edge. If everything looks good put new gaskets in and put it back together.
I don't remember just how an older 40 is set up. If there is a cooling plate on the head you'll have to remove it to get the head off. If this is a saltwater motor you'll probably have a very difficult time getting the bolts out without them breaking. Once the head is off check for damage to the block, piston, and head. Make sure the head isn't warped by checking it with a good straight edge. If everything looks good put new gaskets in and put it back together.
What was I supposed to do today?