What is this part that Fell into the lake

Hi, as I was replacing the starter solenoid today, my dad wondered what this plastic part was that was vibrating on the top of the engine. anyway we cut the engine so I could get closer. I got to it and bumped it, it fell in. Can't find it. Let me explain the part

It is a mercury 35 hp from an 89. It is a black plastic piece about 3-4 inches tall. It is on the top part of the engine next to the flywheel. When looking from on the pontoon deck, it is about the middle of the engine and to the port side of the boat. When properly secured it is about a few MM from the teeth of the flywheel. What happened is it is supposed to be secured by a bolt into the engine casing, there is also a press fit locater pin on the casing for a hole to line up to on this plastic part. well there was no bolt holding it down. It looked absolutely useless. only thing I can think of is it has something to do with the flywheel like some type of protector. I see no function of this item however as with all parts it has to do something. Please let me know if you have an idea as I have no pictures of the part. If someone has a schematic I can show also.


EDIT HAVE PIC

Re: What is this part that Fell into the lake

looks like timing indicater for setting up your timing marks

Re: What is this part that Fell into the lake

ahh that makes complete sense. Thank you. I guess I will need it if I need to reset timing. If not then it is useless. I should have known this. Thank you. Now to find one.

Re: What is this part that Fell into the lake

http://www.mercruiserparts.com/Show...&bnbr=100&bdesc=CYLINDER+BLOCK+AND+THERMOSTAT
part 16, if they have it , a merc dealer may be able to get too. merc parts express was down to look up