svonmiller

Greetings,

I have 1990 twin 350 EFI engines from Mercruiser High-performance. I don't have my notes here at the office but I believe these are Bravo 1 outdrives. The port outdrive has got some sort of leaking that's coming out between the transom and the housing. Below are a couple of pics.

Of course the next step is to pull the drive, but I'm not sure what I'm looking for. One guy at a shop told me based on my description it was a blown yoke seal. Anyone have any ideas?
Thanks!
Stan

GTOFFSHORE

A blown yoke seal will put drive oil in the bildge and out of the bottle. If there is water in the bellows and oil it can be frOm water getting into the bellows and rusting yoke seal.
What you have looks it's on the outside. Do you have water in bildge?

Boat1

The picture shows your hydraulic manifold block to the trim pumps. The two bolts visable hold the plastic cover on, remove those you will find two studs with nuts or bolts. Remove those and the manifold block can be pulled down, two hydraulic lines connect to the top of the manifold from the trim pump. One of those hydraulic lines may be loose or leaking. You can cycle the trim pump while watching the manifold for leaks. I would dead head the pump in the full up and down position and inspect the inner connections.

picklenjim

Looks to me like the seal between the transom and transom assembly is leaking oily/water mix out from the bildge when out of the water. When in the water it probably leaks water in.

blue thunder

Ditto. There is also an oring/gasket that seals the manifold to the transom assembly.

svonmiller

You guys rock.. thanks! I'll have a look in the next day or so and let you know what I find. What everyone is suggesting makes perfect sense. No water in the bilge ever, and never lost any lower unit oil from the reservoirs, so I was always puzzled. Never even thought to check the trim reservoir.

The skinny is that this boat has been dry-docked for three years. I'm now rebuilding the starboard motor. This was happening on the port side, and was happening when I lost the starboard engine. I'm getting ready to get it all back together (engine in the machine shop now) and into the water, and was just about to pull the port side lower unit. But I'll check this out first. If it's a trim/hydraulics issue and not seals, I'll be very stoked.

Thanks again,
Stan

blue thunder

You can be stoked now because it is certainly not the yoke seals. Check your trim reservoir and see if the fluid looks like a strawberry shake. Tranny fluid and water make strawberry shakes.

Boat Doctor

transom rot. bolts rusted on inside of boat leaking between the transom plate assy and hull bolts are not stainless so they will rust if water gets to them check your transom well by taping with hard object (small hammer) and listen for hollow sound.

kubelwagonman

ditto on what boat doc said,,,,if its not leaking yet IT WILL an yu can bet yur gonna be replacing the transom soon as well

racinfever

+1 for boat doc. other guys go back to school!