Re: Head Gasket or something more sinister? -- 2003 Mercury 75hp 4 stroke
Now that I can really look it over in the daylight the pitting on the head is pretty bad. I found two blatantly compromised areas on cylinders #3 & #4 (the two with the lowest compression) and #1 was almost completely through as well. The pitting eroded out a channel underneath the head gasket and allowed water to travel beneath the head gasket and sneak directly between the water jackets and compression chamber in at least 3 places. We found something else kind of interesting, this isn't the original head gasket on the outboard. It has been into at least once before, when we cracked it open, we saw where a technician had marked the head, numbered the head bolts and scored the cam for timing position.This is at least the 2nd time the head needs work.
@Star - I have no idea how many hours are on it there isn't an hour meter and the last owner said he really couldn't even guess at it. I hope you are right! I really do NOT want to go any deeper unless I have to. A buddy is helping me with it, he's a top notch Toyota certified technician, but I get the heebeejeebees thinking about tearing it completely down. I want to keep this at our lake house and use it on the weekends (it will get a lot of use) so I will do whatever I have to do to make it right and make it last a few years dependably, but it creeps me out to think about breaking the crank loose.
@Ticondo - I will pull the rags out and post a few pics of the cylinder walls with the rags out. I don't see/feel any scaring or anything like that, but like you, I worry about the salt having gotten down into the crank case. A lot can go wrong and I have it this far already, it might be worth it to just keep going. My technician buddy is coming over tonight to take a look in the daylight too, we may need to keep going to make it right.
P.S. I hope the iBoats.com folks don't get pissed at me for posting all these pictures!
