Old inline 6 rebuild (sealant question)

Doug Redinger

Seaman
Joined
May 22, 2005
Messages
73
I have an old Mercury inline 6 (merc 850) that is a 1964 model. This old motor runs incredibly well, but it has a water-jacket leak around one of the spark plug holes. No cooling water gets in the engine, it just runs down the block by the spark plugs. I rebuilt this motor 3 years ago and I used permatex aviation sealant when I reassembled it. I am thinking I should have maybe used something else on gaskets other than the aviation sealant. What do you guys recomend for sealant whan rebuilding these old engines. RTV sealant? Gasket cement? Thanks for any help!!

Doug
 

OldMercsRule

Captain
Joined
Nov 30, 2006
Messages
3,340
Re: Old inline 6 rebuild (sealant question)

I have an old Mercury inline 6 (merc 850) that is a 1964 model. This old motor runs incredibly well, but it has a water-jacket leak around one of the spark plug holes. No cooling water gets in the engine, it just runs down the block by the spark plugs. I rebuilt this motor 3 years ago and I used permatex aviation sealant when I reassembled it. I am thinking I should have maybe used something else on gaskets other than the aviation sealant. What do you guys recomend for sealant whan rebuilding these old engines. RTV sealant? Gasket cement? Thanks for any help!!

Doug

I dunno what to use on a rebuild: Doug, but I had a 1976 1500 that was leaking water around two of the sparkplugs and I used JB Weld, (very hard heat proof epoxy putty), to seal the water leak and it worked like a champ!!!!

Hope that helps ya as it sure helped me. JR
 

Laddies

Banned
Joined
Sep 10, 2004
Messages
12,218
Re: Old inline 6 rebuild (sealant question)

Loctite 518 or Master Gasket
 
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