Help identify part. Rubber FWD of shift rod in Upper Gear Case

[vsok]

Engine is 1999 5.0 Mercruiser and Outdrive is an Alpha One, Gen. 2. I need help identifying the part identified by the red arrow in the attached picture. It is a hard rubber (maybe even plastic) part just forward of the shift rod/gear selector rod. For refererenc, in one of the pictures, you can see the hole in the Upper Gear Case where the drive shaft from the Lower Drive Unit goes into. This hard rubber piece looks like it's out of place and I is damaged (possibly from the movement of the shift rod). I have checked many diagrams of the outdrive unit and was not able to pinpoint this part.

 

[Bt Doctur]

It`s the missing exaust shutter http://www.boatfix.com/merc/Servmanl/16/16D7R2.PDF#[0,{%22name%22:%22FitR%22},-82,284,695,797]

 

[Bondo]

Ayuh,..... Welcome Aboard,...... At some time, yer motor was run without decent water flow, which caused the exhaust to run dry, 'n hot, which melted the shutters,.....

That appears to be 1/2 of a shutter,.....

The shutters live in the very top of the y-pipe, under the rubber couplin',....

 

[vsok]

Thank you both.

Can you tell me if this is the location where the shutter should be or did it migrate from another location and happen to get stuck here? Is this something that need to be addressed right away? We took the boat out yesterday for a couple hours and the boat ran fine with the exception of very strong gasoline smell. Could this cause the gasoline smell? I guess my questions is due to the fact that I do not know the function of the shutter and I'm a bit new to marine mechanics. I work on cars growing up, but this my first boat and I'm finding that marine hardware is much different than what I'm used to, but I know I will pick it up.

 

[nola mike]

Like Bondo said, they live at the top of the y pipe, behind your exhaust manifolds in the engine compartment. They prevent water from going backwards into your engine, particularly if you slow down too fast, get a wave hit you from behind, etc. It burned off and left its home, lodging in your outdrive. You want to replace it as soon as possible, but you've been running without it for who knows how long. Gasoline smell is a separate issue.

 

[Bt Doctur]

could open the link and see for yourself too

 

[vsok]

I will start looking into replacing the shutter and removing the dislodge portion in the outdrive. Just got done removing the lower drive last weekend to replace the impeller and drive oil so I already got that part pinned down, at least.

It looks like there’s smaller bits that broke off the shutter, should I be very thorough in finding all the small pieces in the system or should I be safe in just removing the larger, more obvious pieces?

Any tips in making access to the y-pipe easier would be much appreciated also.