Brass plug?

[Scott215]

He is talking about the intake manifold. Not the exhaust. Does require some knowledge and being careful not to get anything in the engine when you pull it off. Take a lot of pictures

 

[george resto]

Thanks Scott. So the Intake manifold gasket is the culprit? I’ll order one asap.

 

[Bill Curtis]

Thanks Scott. So the Intake manifold gasket is the culprit? I’ll order one asap.

There are 2 seal strips where the front and back of manifold meet the block. The intersection of where the intake gaskets meet those 2 strips is where it usually leaks. Replace intake gaskets, those 2 strips and add a blob of form a gasket at that intersection assuring it gets under the gaskets, too, to fill where the heads meet the block (that is usually the source of the leak).

See this video at around the 7 minute mark

 

[Scott215]

Very important to follow these directions the stock ones the come with the kit will blow out. Please use a good bead of black or grey rtv

 

[george resto]

I wanna thank you guys for all your advice! Spent the day taking it apart. Took lots of photos to backtrack if I forget a connection.
I Replaced the thermostat while it was exposed. Gotta order the manifold gaskets since advance auto had none left. Brought a tube of the permatex. I guess I’ll scrape and prep the block mating surfaces in the meantime.
The only thing that has me a little nervous is putting back the distributor. I took photos and removed it carefully.

I’m assuming if install it back, the exact same way it was, the timing should be fine?

 

[george resto]

.

 

[techmitch]

If you marked the distributor to block exact location and exactly where the rotor was pointed on the distributor you should be fine with that. Note: Strictly follow the intake manifold torque spec. and torque sequence. Give the silicone in the corners time to fully cure before starting the engine back up.

 

[Scott215]

If you get in a bind with the distributor, just ask here and we will help you get it back so you can start it and time it

 

[george resto]

Assistance is required my friends.
Found this guy online (same 4.3) using a slightly different intake gasket.
Here’s a picture of his(6104)and a picture of the one I pulled outta my intake(6097)…
Can I use either one? Mine has this unknown metal plate.

 

[Bill Curtis]

That metal plate blocks the heat crossover in the manifold. Not uncommon.

Not sure that one in the screen shot will do (if your heads are the same as pic), as it neither blocks it off, or seals the crossover. Can see it splits it in the middle. That gasket is the wrong one for that head in the pic.

Show a pic of your heads without the manifold so we can see what is actually there.

 

[Scott215]

Get factory Merc gaskets. Take yours to a dealer and get them

 

[george resto]

Every picture I try to upload.. I keep getting a message that the file is too large. I tried 10x and gave up.

that small passage under the metal plate isn’t a passage at all. It’s a cutout about an inch deep. Under the top of the manifold itself are no cutouts at all.

That metal plate blocks the heat crossover in the manifold. Not uncommon.

Not sure that one in the screen shot will do (if your heads are the same as pic), as it neither blocks it off, or seals the crossover. Can see it splits it in the middle. That gasket is the wrong one for that head in the pic.

Show a pic of your heads without the manifold so we can see what is actually there.

 

[Scott215]

Call a MerCruiser dealer give them your engine serial number and get the proper gaskets please You don't want to do this again and get water in your engine

 

[Scott215]

I don't know if you have the left gasket and the right side head or what. But Please Get The Right Set Of GASKETS

 

[techmitch]

Every picture I try to upload.. I keep getting a message that the file is too large. I tried 10x and gave up.

that small passage under the metal plate isn’t a passage at all. It’s a cutout about an inch deep. Under the top of the manifold itself are no cutouts at all.

Enter your serial # here https://public-mercurymarine.sysonl...est&NA_KEY=NA_KEY_VALUE&langIF=eng&langDB=eng

 

[ttmott]

Every picture I try to upload.. I keep getting a message that the file is too large. I tried 10x and gave up.

that small passage under the metal plate isn’t a passage at all. It’s a cutout about an inch deep. Under the top of the manifold itself are no cutouts at all.

That small passage is originally for intake manifold heat. I don't think the marine manifolds use that feature.
Use Permatex Right Stuff for the end seals gasket maker. Other gasket makers just will not last in a hot oil environment.
It is essential that the surfaces be squeaky clean. Final wipe-down I use acetone on a white rag to make sure.
Dry-fit the manifold and check how big the end gaps are which will guide you on the bead size of the Right Stuff. I have seen anywhere from 1/32-inch to almost 1/4-inch in that gap. You should be in the smaller gap range as the components are OEM.
Again, for the gasket maker to adhere to the surfaces they need to be super clean.
I install the manifold and lightly tighten the bolts. Then allow a couple of hours for the gasket maker to set up and then torque the bolts down.

 

[ttmott]

That small passage is originally for intake manifold heat. I don't think the marine manifolds use that feature.
Use Permatex Right Stuff for the end seals gasket maker. Other gasket makers just will not last in a hot oil environment.
It is essential that the surfaces be squeaky clean. Final wipe-down I use acetone on a white rag to make sure.
Dry-fit the manifold and check how big the end gaps are which will guide you on the bead size of the Right Stuff. I have seen anywhere from 1/32-inch to almost 1/4-inch in that gap. You should be in the smaller gap range as the components are OEM.
Again, for the gasket maker to adhere to the surfaces they need to be super clean.
I install the manifold and lightly tighten the bolts. Then allow a couple of hours for the gasket maker to set up and then torque the bolts down.

Also the oil pressure sender is back behind the manifold next to the distributor and they can leak causing the exact same conditions you are experiencing. So, check that out also.

 

[george resto]

All set. Everything back together and started right up. No visible leaks while running. Once I get back to the lake I know for sure. Thanks again and I will keep y’all posted

 

[george resto]

All set. Everything back together and started right up. No visible leaks while running. Once I get back to the lake I know for sure. Thanks again and I will keep y’all posted

After all that work.. unfortunately no luck. Somehow this motor is still spitting oil. New valve cover and intake gaskets. This is a complete mystery to me. Well, the season is pretty much over so I think it’s time for the boat doctor to step in.. Unless anyone has any ideas…. It seems to be spitting out all over the starter and even onto the dividing wall(see photos)

 

[george resto]

After all that work.. unfortunately no luck. Somehow this motor is still spitting oil. New valve cover and intake gaskets. This is a complete mystery to me. Well, the season is pretty much over so I think it’s time for the boat doctor to step in.. Unless anyone has any ideas…. It seems to be spitting out all over the starter and even onto the dividing wall(see photos)

After all that work.. unfortunately no luck. Somehow this motor is still spitting oil. New valve cover and intake gaskets. This is a complete mystery to me. Well, the season is pretty much over so I think it’s time for the boat doctor to step in.. Unless anyone has any ideas…. It seems to be spitting out all over the starter and even onto the dividing wall(see photos)