Permatex or not to permatex... that is the question.

olddogmike

Seaman Apprentice
Joined
May 25, 2003
Messages
39
I will be installing a new exhaust maniflod and riser elbow on my 1995 3.0LX Mercruiser this weekend. After reading the Mercruiser manual I am unclear as to weather or not I should use a gasket sealer on the manifold gasket, the riser gasket and the carb gasket. I would also like to find out if anyone knows the torque values for the exhaust manifold bolts and the carb. bolts. Thanks for all the help that has been sent my way for the past 2 weeks in dealing with a water in oil problem. :confused:
 

Bob_VT

Moderator & Unofficial iBoats Historian
Staff member
Joined
May 19, 2001
Messages
26,046
Re: Permatex or not to permatex... that is the question.

Hmmm, well yes you can use the permatex but use the high heat orange colored one. As for the torque values the carb should be tight (I really don't have a value) and the exhaust manifold should be 20 foot Lbs.<br /><br />Don't take my word for it but I would invest in the proper manual before you proceed...those parts are too much money.<br /><br />Bob
 

akriverrat

Chief Petty Officer
Joined
Oct 31, 2002
Messages
588
Re: Permatex or not to permatex... that is the question.

exhaust manifold gasket no sealer. permatex ultra black has literally replaced many gaskets in modern engines. intake manifold on my 4.3 uses gaskets where it mates to heads and a bead of ultrablack front and rear. a thin layer on riser and carb is ok. if any oozes out it is also oozing in possibly blocking passages. gm spent big bucks developing this stuff.
 

ODDD1

Lieutenant Junior Grade
Joined
Jan 23, 2001
Messages
1,054
Re: Permatex or not to permatex... that is the question.

nope, nope, an nope....all these gaskets go on dry....the only thing permatex/silicone does is make a mess...
 

snapperbait

Vice Admiral
Joined
Aug 20, 2002
Messages
5,754
Re: Permatex or not to permatex... that is the question.

I'm in total agreement with Odd1... Negative on the sealant... Especially the carb gasket... Contact with gasoline will break down the sealant, just causing vacuum leaks later on...
 

sea wolf

Lieutenant Junior Grade
Joined
Apr 3, 2002
Messages
1,219
Re: Permatex or not to permatex... that is the question.

don't use it on the carb gasket. but on the manifold & riser absolutely. i don't care what merc says. trust me. just don't go overboard with the stuff. and use permatex ultra black, not blue or orange or any other color.
 

record hunter

Petty Officer 3rd Class
Joined
Apr 22, 2003
Messages
99
Re: Permatex or not to permatex... that is the question.

I replaced my manifolds and elbows and end caps .After receiving all the parts and a catalogI read not to use sealent so against my better judgment I decided for once to do what the book was telling me. Well guess whatI had two leaks So I took it apart and used permatex high tack gasket sealent I use it on waterpumps and most everything never had a problem yet.As far as your carb absolutely not anyone who tells you to use it on carb does not know what they are talking about.
 
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