Leak in Exhaust Y-pipe

[flatwater]

I have installed the Cobra to SE116 conversion kit and I am currently in the middle of break in. Today my bilge kicked on which is very unusual. When I pulled the engine cover, I could hear water dripping. I laid down and could see water dripping from somewhere near where the exhaust y-pipe meets the gimbal housing. Without removing the engine I can not see more specifically where it is leaking. Any idea what seal I could have missed to cause this leak. The boat was fairly water tight before the conversion.

[admin]

As far as the conversion goes, there is only one area that water is a concern, and that is the u-joint bellows. It is possible that the u-joint bellows wasn't clamped tight enough, and pulled off the flange. Also when putting the drive on, if you missed the large square oring in the bell housing, that will cause a leak. It is also possible that when installing the drive the u-joint assembly grabbed the o-ring and pushed it into the bellows causing a leak.

The shift cable hose should be above the waterline, but that's an obvious one if it is leaking. The exhaust pipe could be leaking, but unlikely if it was fine before.

I would say pull the drive and do some investigating.

Tech Support

[flatwater]

I finally had time to pull the drive back off. It appears that the large o-ring between the drive and the bell housing got pulled off during installation. When I pulled the drive the o-ring and a silver metal ring of the same size both came out. The o-ring was cut in two places.

Now I found the problem. The obvious fix is to replace the o-ring and re-install. Since I had water laying on the inside of the u-joint belows and obvious water around the drive shaft, I plan to clean everything that was wet, re-lube the gimbal bearing and u-joint bearings until I get fresh grease. Is there anything else I need to do before reassembly? I am not sure of the path the water took to get from the drive shaft cavity to my bilge but I would like to avoid pulling the engine if possible.

Thanks for your quick reply.

Flatwater

[admin]

I think you got it figured out. everything you said sounds right. The water probably got past the seal behind the gimbal bearing. That's a good thing though, it showed you that you had a problem. If it didn't get in the boat, you wouldn't know it was leaking. For a trailer boat it's good, if it stays in the water all the time, then it would be bad as it could eventually kill the battery running the bilge pump.

Tech Support

[flatwater]

Thanks. Now I need to replace the o-ring. It has a tear. Is that a standard Merc part or is it specific to the conversion. If Merc, do you have the part number so I can get it locally.

[admin]

You will need to buy a complete mounting gasket kit. If you tell any marine place you need a mounting gasket kit for a Mercruiser Gen II, they should know what you mean. The OE number is 94996Q2

Tech Support