Gasket sealer on reed plate?

gdc0581

Seaman Apprentice
Joined
Jul 23, 2009
Messages
43
I'm rebuilding the power head on my 1977 75HP Evinrude. I'm a little confused as to whether I should use gasket sealer on the gaskets on either side of the reed plate. The factory service manual says to use OMC gasket sealer on all gaskets except those that are specifically labled not to use sealer i.e. head gasket. One post I read says to use only grease or oil on carb and manifold gaskets because of the danger of plugging small passages with gasket sealer. The Seloc manual is also silent on the subject. For example it specifically says to use sealer on the exhaust covers, but says nothing either way about the reed plate. I don't think the original gaskets were sealed, but I can't be sure. They were pretty difficult to remove.

A second question: Is Mercruiser bellows adhesive a suitable substitute for OMC Type M on the spaghetti seals for the crankcase halves? I ask because I have some and the recommended replacements for type M seem to be hard to come by in my rural island environment that is a ferry ride and a two hour drive from my local Evinrude dealer. Should I consider using gel seal in addition to the spaghetti seals?
 

ezeke

Supreme Mariner
Joined
Sep 19, 2003
Messages
12,532
Re: Gasket sealer on reed plate?

3M Scotchgrip 847 is the replacement for OMC Adhesive Type M, but don't use it on the crankcase halves, just on the spaghetti.
 

gdc0581

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Jul 23, 2009
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Re: Gasket sealer on reed plate?

I think I've read all of the threads referencing OMC type M and I know about scotch 847, marprox 1000, boat armor 1000 ... The problem is that I can't get any of it locally. I could order it off the internet and wait a week or take a day and go to Seaway marine, who has everything. I have a tube of Mercruiser bellows adhesive, which seems like a similar adhesive. It's sticky, non-hardening, and is used for sticking rubber to metal. Has anybody used it and the above mentioned adhesives who could tell me if it will or won't work.
 

R.Johnson

Rear Admiral
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Sep 24, 2003
Messages
4,446
Re: Gasket sealer on reed plate?

On the intake manifold, or reed boxes' I always used grease such as OMC triple guard, but that was on my own engines. I never had any problem doing this. What does the manual say?
 

gdc0581

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Jul 23, 2009
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43
Re: Gasket sealer on reed plate?

On the topic of "Installation of leaf valves and intake manifold" it says "Using new gaskets, install leaf valve and plate assembly and intake manifold. Be sure new gaskets match all openings."

In the section on "Reassembly of power head" it says "Always use new gaskets and seals throughout when reassembling the power head. Apply OMC gasket sealing compound part number 317201 to both sides of gaskets and to outside of metal cased seals" It also says "make sure all oil holes and passages are open.

I'm pretty sure that gasket sealer was not used on the original assembly or it was used only near the attachment bolts. There was an obvious separation between the reed plate and the gasket between the reed blocks. However, where the reed plate bolts to the crankcase and intake manifold I needed to scrape the old gasket off, indicating that sealer may have been used in these locations.
 

82 Evinrude 70

Recruit
Joined
Mar 14, 2011
Messages
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Re: Gasket sealer on reed plate?

Hi, I'm in the same situation and am curious what you ended up doing, grease, sealer or nothing at all?. Thanks
 

DargelJohn

Petty Officer 1st Class
Joined
Feb 14, 2010
Messages
337
Re: Gasket sealer on reed plate?

I have been told in past and have read in manuals that you should never use any kind of sealant on the Intake side of an engine. All gaskets are assembled dry.
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: Gasket sealer on reed plate?

You don't want to use any type of sealer on the intake manifold or reed plate gaslets. If the c/c halves have a gruve in them for an oring type seal, use 3M 847 sealer. If no gruve and flat surfaces use Gel-Seal. Head gaskets and base gaskets will sometimes say "use no sealer". If not, put BRP gasket sealing compond on them or Permatex #3 liquid sealer on them. You only use a light coating of grease on the c/s orings.
 
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