Mercury sport jet 120 hp water in manifold

[unhappycamper]

I have had problems with this boat for over a year and a half. We thought the bottom carb was getting fuel at first.Than we changed the plugs and coils. I recently found water in the bottom two cylinders and decided to take off the manifold and inspect. Sure enough, there was grey sludge where there shouldn't of been.(around exhaust port) The manifold gasket doesn't seem to be broken but it has failed anyway. Could this have happened by starting it out of water because the gasket looks a little burnt. What is my next step. Thanks in advance.

 

[emoney]

Re: Mercury sport jet 120 hp water in manifold

I know that you can blow a ride seal starting these out of water. Probably better & quicker answers in the "PWC-Jet boat" forum. Lots of guys working on theirs over there. It is, though, the one motor that you simply can't start out of water. I had one a few months ago. Sounds like this one somebody didn't believe that because the exhaust is under water when operating.