Inline 6 serial 5314656

[mlbinseattle]

If you can positively determine that there are no leaks coming from the inner water jacket, it's best not to mess with it. Any water leaks would wash away the carbon in the area of the leak.

Note that the inner bolts are epoxied in place with a special compound called Resi-Weld. If you do have to remove the cover, it's best to heat the area around the bolts to soften-up the stuff and prevent bolts from breaking. You can use Loctite Red 571 on the bolts when you reassemble.

If you see no leaks, one good thing to do is check the inner cover for any cracks. If everything looks good, leave it alone. It can be a Big Bag of Worms, thus the recommendation.

Ditto what Chris said on the Permatex #3 for the bolts. Permatex will seal the bolt and prevent any salt/deposits from ever forming around the bolts and causing them to seize.

If the gaskets you get are dry, use Permatex No. 3 as a gasket dressing. Just a thin coat, no need to slather the stuff on. If the gaskets have glue on them (they'll be shiny & sticky), don't use any dressing. Be sure to torque all bolts to the proper values.

If you don't have a manual, check out this online resource:

http://www.boatinfo.no/lib/mercury/m...40-115.html#/0

And the crankshaft seal can only be accessed by pulling the powerhead. You don't have to split the cases to remove the lower end crankshaft end cap, where the seals reside.

If you find that you're sucking water into #6 after replacing the exhaust manifold gaskets, likely the lower crank seals are bad and water is getting in from there.

HTH.........ed

I don't mean to hijack this thread, but I'm in a similar situation with replacing gaskets. I have a recent thread on this subject if you care to look. I'm at the point of pulling the exhaust cover. I don't want to pull that inner cover unless I absolutely need to. I pulled the water jacket cover on the backside, yesterday, and that was a real pain. I need to drill/tap 5 out of 12 1/4-20's for that, so, I agree that there is no need to open a big can of worms unless absolutely needed.

You stated that, "If you see no leaks ...". Question is, how would you check for leaks? Would it be a lack of carbon buildup as you stated? Specifically, what area should I be on the lookout for?

Any help is appreciated.

 

[emckelvy]

I don't mean to hijack this thread, but I'm in a similar situation with replacing gaskets. I have a recent thread on this subject if you care to look. I'm at the point of pulling the exhaust cover. I don't want to pull that inner cover unless I absolutely need to. I pulled the water jacket cover on the backside, yesterday, and that was a real pain. I need to drill/tap 5 out of 12 1/4-20's for that, so, I agree that there is no need to open a big can of worms unless absolutely needed.

You stated that, "If you see no leaks ...". Question is, how would you check for leaks? Would it be a lack of carbon buildup as you stated? Specifically, what area should I be on the lookout for?

Any help is appreciated.

Usually, if there are leaks into the exhaust area, you'll see obvious places where water has washed away carbon buildup. So it'll look very clean. On the inner cover, pay special attention to any areas that look badly corroded (especially if you run in salt water), any cracks in the cover, or any bulged-out gasket material.

If the inner cover looks good, no abnormal corrosion, gaskets seem intact, no signs of leakage -- better to leave it alone.

Hope that helps.........ed

 

[mlbinseattle]

Usually, if there are leaks into the exhaust area, you'll see obvious places where water has washed away carbon buildup. So it'll look very clean. On the inner cover, pay special attention to any areas that look badly corroded (especially if you run in salt water), any cracks in the cover, or any bulged-out gasket material.

If the inner cover looks good, no abnormal corrosion, gaskets seem intact, no signs of leakage -- better to leave it alone.

Hope that helps.........ed

Yes, it does. I haven't pulled the exhaust cover, yet, but the engine is 39 years old, and so far, all the other gaskets have been toast. I suspect the water jacket cover gasket won't be any different. I'll keep my fingers crossed. Thanks for the response. I do appreciate it.

 

[Chris1956]

Look in the nooks and crannies of the inner water jacket cover for places the aluminum has rotted away. That is another place for the water to leak. Often holes are found in the exhaust baffle. (the plate under the water jacket outer cover)

 

[mlbinseattle]

Look in the nooks and crannies of the inner water jacket cover for places the aluminum has rotted away. That is another place for the water to leak. Often holes are found in the exhaust baffle. (the plate under the water jacket outer cover)

Chris, looking at the exploded view of my engine, I only see a water jacket cover plate and a gasket. Is the baffle an integral part of the cover plate? If there's holes in that baffle, how would one know without pulling the water jacket cover?

I have a few more things to do before pulling that exhaust cover, but I hope to accomplish that, today. I'll post pics and start a new thread. I'll also tag you and emckelvy to get your inputs.

 

[Chris1956]

'76 Merc 850 right. Look at item 20 on this page. http://www.crowleymarine.com/mercury-outboard/parts/475_11.cfm?mdl=EE2EBM

Item 20 is the exhaust baffle. It is located under the exhaust cover, and uses the same bolts to hold it on.

 

[mlbinseattle]

Got it. Thanks. That's what I was calling the divide plate.