Exhaust gasket and shutter questions 83 mercruiser 260 5.7L.

[wellcraft-classic210]

I Pulled the Exhaust risers off the old tub for an inspection and they seem to be in great shape for their age 1983 -- freshwater use only.



I found what seems to be a 3 piece gasket with a thin stainless steel spacer as the center section under the risers -- I was not finding this same part in the parts listing -- only finding merc 863724 which does not seem to have all 4 water passage openings and is a 1 piece ( Is that OK ??? ) ( see pic )

I did find 1 shutter missing and the other was binding slightly

Also -- Is the shutter sticking / binding typical -- Any solutions ? ( Y pipe is round not oval at shuutterd)

Any advice on fishing out the old one ?? I am thinking I need a camera scope to find it and will then try to remove it based on what I can find.


The mating Surfaces seem a little rough-( see pic ) - given the lack of rust I assume the prior owner leaned these up but did not lap or mill them and replaced the gaskets


Hoping these links work --


https://drive.google.com/file/d/1WBRIbWcEmRUVU-5hRbHQ7t2iXGhkVg4X/view?usp=sharing
https://drive.google.com/file/d/1WkVucZsNGD40nWDBLy_gufU_L_ehPS12/view?usp=sharing
https://drive.google.com/file/d/13xZn1S9X_Pmnd54RG8CCZXSmo1SRBkFr/view?usp=sharing
https://drive.google.com/file/d/10-FdOi6KZVJoJ7keiXOaweIjlz_kgXoe/view?usp=sharing


The engine is a 5.7 liter with a quadrejet ( merc 260 ) ​​​​​​​


Thanks for reading !

 

[Bt Doctur]

4th pic is suspect, try filing it with a fine flat file or take a slight cut with a milling machine

 

[wellcraft-classic210]

Yes Doc -- I will resurface them --- hoping the manifold surfaces are better// need to clean them up to see.

 

[wellcraft-classic210]

I found part number 27-863726 which looks closer for the riser gasket -It did not come up as I searched part lists for my year & Model -- not sure if I need 4 of these --

https://www.iboats.com/shop/mercury-gasket-exh-elbow-c-e-o-open.html

 

[Bt Doctur]

most raw water cooled motors use the 2 slot/2 hole gaskets .If using risers the 4 open slot goes on the manifold first, then the riser, then the 2 slot one then the elbow

 

[wellcraft-classic210]

Yes -- It looks like someone used a riser gasket set on the elbows -- as I don't have risers -- Not sure why -- Perhaps a little more durable or just what was around at the time ??

Also -- My apologies --- I got my terms backwards & referred to elbows as risers above--( No risers involved here)

OK it seems I should order the 2 slot gaskets and 1 per side will be sufficient if the mating surfaces are cleaned up ( flat and no pits ) // will order Mercruiser brand as some look cheap like blue paper

Still need to find the missing flapper in the exhaust // and that design seems pretty marginal -- Any input is welcome

I have heard of an upgrade on the flapper / shutters but it seems that's for oval and mine is round

Thanks for any advice or following!

 

[wellcraft-classic210]

The filing work surprisingly well on the Elbows -- I need to do a little more work to achieve final flatness as 1 corner is low when checking with a straight edge.

Ordered new gaskets and shutters

I still need to get back out in the boat to work on manifold surfaces and and find that missing shutter section.
( Still pretty cold here in VT)

 

[wellcraft-classic210]

Having trouble getting good flatness on the risers when check with a straight edge -- My files are not perfectly flat and i am seeing about .015 in gaps in some places

It seems a may need to try some kind of lapping-- HMMM

 

[wellcraft-classic210]

The good news
I was able to lap the elbows to a nearly perfect flatness using adehise backed paper attached to my cast iron table saw top.

The bad news
I can see the shutter at the bottom of the y pipe using a borrowed boroscope camera --but I have not been able to move it much as it seems lodged and the grabber tool comes off when i try to pull it along --HMMM

It seems to be near the 2 smaller holes in the transom that allow water to exit ( as seen when on the wagon and running with muffs )

I may try making a hook etc -- But it seems I need to pull the outdrive as well.

 

[Bt Doctur]

Most times you remove the drive, remove the shift rod, and remove the shutter pieces
The area with the exaust relief holes is the transom part not the Y pipe part

 

[wellcraft-classic210]

OK I will try that -- Still some snow on the ground here -- so I was avoiding that if possible. ( No worse than the wet soggy ground that follows the snow melt I guess)

Thanks for the advice !!!!

 

[wellcraft-classic210]

I pulled the out drive and still could not access the shutter-- that passage is open

Their is a separator in the y pipe casting for the lower transom water exit -- so its in that which is the lowest point -- Cant find a way to grab on to it -- but I can see it with a bore scope ( tried a grab tool & variety of wires from the drain port)

It seems that pulling the motor and y pipe may be needed to remove it --

Has Anyone ever had this exact issue with 3 inch ROUND Y using shutter 99370A2 ????

Given its not in the main exhaust channel -- wondering if I should just leave it --

Pic of y pipe lowest section

https://drive.google.com/open?id=1Wyyqw0jRcf5CzMDzJTWw2oxzLsxcsYuU

https://drive.google.com/open?id=1B4MODQO4EoJ023AQ_MkIvmKqOu2UUiwP

 

[wellcraft-classic210]

I got the flapper to move into the main passage --- its now stuck down near the bottom of the y main exhaust passage.

I can grab on to it with the grabber but its getting caught in the last turn.

I think I may need to bend it and then get it with the grabber.

 

[wellcraft-classic210]

Finally made some progress -----

I made a sketch of gen-1 Y pipe -- Once i got the old shutter into the main exhaust passage I was able to pull it through and out.

The trick was to make sure it stayed out of the lower passage by plugging that off with a rag and pulling it through with a home mad rig of polystyrene foam sections hooked to a plastic tube .

 

[wellcraft-classic210]

Also -- Per the pics above-- The old shutter was made of solid plastic -- Merc# 92802

I was concerned it would wear a hole in the y pipe if left in place -- but being plastic ( Not Metal like the newer ones ) it may not have become an issue.

On to final flatness lapping of the manifolds , Paint and reassembly