Merc 3.0 cylinder pressure???

[guambob]

I have a Merc 3.0 (1988) It runs fine in the yard. When i get it in the water(salt) it starts up fine and runs good for a couple minutes. Then it boggs out and wont restart. when i pull the plugs, i have 1-2 cylinders that release pressure. What should i be looking at next????<br /><br />All plugs, wires, coil, fuel lines are new. good spark on all plugs.

 

[denniz]

Re: Merc 3.0 cylinder pressure???

Thats a new one. Start with compression test. Any signs of water in the oil?

 

[flashback]

Re: Merc 3.0 cylinder pressure???

probably need the head re-worked, sounds like the valves are hanging up in those two cylinders..just my 2cents........goodluck.......