1985 OMC 3 liter, mystery part from exhaust, help!

[captaincaveman]

hello i have a 1985 OMC 3 liter stern drive engine i just bought this boat and was running it the other day for about 5 mins and after i shut it down i notice somthing on the ground under my engine that was not theer when first started it is a black rubber seal of some sort it looks to be ripped in half and it also has an inner peice of sleel surrounded by rubber it also looks to have some slight carbon build-up on it so i assume it might have poped out from my exhaust vent as my outdrive was in the up position while i was running the motor, this part being half a circle is about the size of a half "jos louis" chocolate covered cake snack rough 4" x 2" i have no idea where this peice of rubber came from and would like to know where to start looking if anybody has an idea so maybe the exhaust has some kind of internal seal? only allowing exhaust to exit and keeping the water out i'm stumped! please help!

 

[scipper77]

Re: 1985 OMC 3 liter, mystery part from exhaust, help!

You say you found this on the ground and under your engine. Was I found in the bilge or on the ground under the outdrive?

I no nothing about OMC's but with mercruisers it is not good practice to run the engine with the outdrive up.

If it is a lower unit seal below the water line be aware that this could be a potentially dangerous situation if you put the boat in the water. Hopefully someone will be along soon who knows more than I do to help you out.

 

[bugzy_1]

Re: 1985 OMC 3 liter, mystery part from exhaust, help!

It sounds like a piece of an exhaust flapper that should be in the exhaust riser.
The flappers are steel covered with rubber at least on my merc.
Not sure about OMC
Good luck!

 

[captaincaveman]

Re: 1985 OMC 3 liter, mystery part from exhaust, help!

my tilt motor is fried it was when i bought it, i read on another site it's not recomended to run engine with stern drive up aswell but said it would be ok for several minutes while not exceeding 1000rpm also it was not in gear i had just throttle on but thanks for the advice this is scary so i won't be running it again till i get a tilt motor back in it, as far as the exhaust flapper that sounds about right i looks to me like it could be a large rubber reed (not exactly but same concept for sure) what is involved with the disinigration of this part is my engine in trouble already or as long as i don't start it anymore and keep it out of the water, will i be ok till the repair, the transom seal is tired and i will be replacing it in spring would this help to gain more access to this particular problem? Thanks! for all your help so far guys this site rocks! very helpful!

 

[scipper77]

Re: 1985 OMC 3 liter, mystery part from exhaust, help!

A picture would really help identify the part.

 

[Don S]

Re: 1985 OMC 3 liter, mystery part from exhaust, help!

i read on another site it's not recomended to run engine with stern drive up aswell but said it would be ok for several minutes while not exceeding 1000rpm

You need to read things on the internet that pertains to your type of outdrive. That is general information on boats with bellows and ujoints and gimbal bearings, buy you have a stringer drive and none of those parts.
You have ball gears, and you do not want to run the ball gears with the drive tilted up all the way.

 

[captaincaveman]

Re: 1985 OMC 3 liter, mystery part from exhaust, help!

here is a pic hope this helps there is a number on the other side witch is smooth rubber # is 981927 with this company logo below [m] (in a full square) with a circle around it as you can see i'm showing the side with the exhaust carbon build up the other side is clean so i assume this side in the pic is the side facing the engine but not sure? hope this pic works here goes

 

[Don S]

Re: 1985 OMC 3 liter, mystery part from exhaust, help!

Exhaust shutter, or flapper or what OMC called an exhaust seal.
Item #42 in the picture, same part number.

 

[captaincaveman]

Re: 1985 OMC 3 liter, mystery part from exhaust, help!

ya Don S. that wasn't too smart, do you think i've done perminate damage to it? was ran for about 3-4 mins low throttle? let me know thanks, and as far as the diagram is that the intermediate housing? and is the flapper located on the engine side of that housing? is that a big job if i have the transom seal and sterndrive already off? i just traded my 1989 honda CR250 dirt bike for this boat last week, your hearing all the bad stuff but it's acually a pretty clean little boat, i wasn't prepared to spend a great deal till spring but everything seems to be adding up ontop of the winterizing cost of oils, gas, stabilizers,enviromental antifreeze now i might not be able to winterize it unless i fix these other problems i'm not sure, i was going to wait till spring for the prop and transom seal (no sence putting a new seal through the winter) so let me ask what youz think-- ebay sells OMC tilt motors for $140 and my local dealer wants $310 for OMC are the ones sold on ebay different are they Junk? or better is there anyway to actuate or turn the tilt manually if i'm carfull? (maybe from inside possibly using the origanal shaft out of the old tilt motor hooked up to a ratchet or somthing like that) and if that was possible could i even run this motor with the sterndrive down all the way, but with the flapper missing? i'm not cheap i know boats arn't free but times are tough right now i'm just starting to get busy but for now i can olny afford the items that can't wait till spring, i'm just trying to winterize it, let me know what youz think, Thanks! again guys