So I'm in the process of putting a couple new motors in the boat. Pulled the drives/motors and in the process of undressing the back of the motor (coupler, housing, flywheel, etc), these small cups where sitting loosely between the coupler and flywheel. It appears there might have been a plastic sleeve over the outside to facilitate a better fit at one time, any help identifying these would be appreciated.

no one has seen this?

What engine model and year are you working on?

Can't say that I've noticed that part before but looking at a photo of a similar type coupler backside, it looks like yours maybe sticking out further then the one linked below which is a big block...Plus you can see some sort of plastic looking part.
http://i.ebayimg.com/00/s/NDgwWDY0MA==/z/QGMAAOSwNSxVVO3I/$_12.JPG
http://www.ebay.com/itm/Mercruiser-C...item1c53019eea

Are both couplers doing/look the same?

It looks like a cap off a small grease cartrdige.

Hi LMD, both motors had them and they are 496 HOs with Imco extension boxes (so longer drive shafts). I couldn't find anything online, but it looked like they might have been intially installed to prevent grease from discharging into the cavity in the end of the crankshaft or void between the coupler and flywheel?

This is the stock OEM 496 MAG and the HO 496 thru out all serial number runs that was used by Mercruiser pic to compare

http://www.ebay.com/itm/OEM-MerCruis...-/121026897294

They use to come with shipping dust cover cap.

Seriously, the builder assembled with the shipping cover still on? * * sigh * * not surprised!

Thanks for the help identifying this BUP!

Good call BUP.

Wonder how hard they had to jamm or mallet the drives on ? Ugggghhh.