Tilt/trim gasket bilge leak?

[bashr52]

I pulled my engine and Y pipe today to diagnose what I thought was a cracked Y pipe which was letting water into the boat up to the level of the bottom of the pipe. The pipe looks perfect, still nicely painted black, no signs of corrosion, cracks, holes, etc. The O ring was still intact and the mating surfaces were all clean. The only thing that is down there at that level is where the tilt/trim hoses pass through to the manifold. Has anyone ever had an issue with that manifold gasket leaking and letting water into the boat? I replaced all the bellows and shift cable grommet last year with no change, so I'm running out of things to look at.. nonvisible signs of issues with the transom in that location, fiberglass was all still intact and no signs of leaks or corrosion around that area.

 

[achris]

Now you have the engine out, I would put the Y-pipe and the drive back on and take the boat to the launching ramp (when it's quiet)... Back the boat down into the water to a level a bit deeper than normal, then just get in and have a look see where the water is getting in... As for the gasket... They do leak, but not very often.... Other places include, the main gimbal housing seal, and, as you have suspected, bellows, and anywhere hoses or wires pass through the housing (trim senders, water hoses, oil reservoir hose, speedo pickup). One other possibility is a cracked gimbal housing...

Chris...........

 

[TurtleTamer]

Or while you're on the trailer, fill the bilge up with water to the bottom of the drive and see if water is coming out where the manifold gasket is.

 

[bashr52]

Cleaned and filled the bilge last night to test for leaks. Filled it up to the top of the engine mount stringers (about half way up the Y pipe), and let it sit while I ate dinner. Came out to a dry transom, water level where I left it. Next step will be install the drive, strap the boat to the trailer to prevent it floating off, and back her into the water...

 

[bashr52]

Slapped the drive back on last night and took it around the corner to the boat launch. I strapped the back of the boat tight to the trailer to prevent it wanting to lift off, and backed her in deep. Source of the leak was immediately apparent. While the Y pipe is in great shape, whoever last installed the engine either used to long of bolts for the rear, or forgot a washer/spacer. When they cranked the bolts down tight they were long enough to make contact with the top of the Y pipe and actually start biting into the casting. Both sides had signs of interference, but the starboard side was completely through and had enough of a pin hole that is was shooting out water like a fountain. New used Y-pipe on the way to fix the issue.....

The hole is small enough I may have had some luck trying to patch it, but since it's not an easily accessible part, and its a source of water intrusion, I'm not taking any chances.