powerhead to adapter gasket: sealer?

[WestPoint]

I have a 86 Evinrude 90 that's probably leaking at this gasket. The OMC manual for this year says to apply gasket sealing compound to a new gasket. The Clymer manual I have (printed 1992) that covers this engine states not to use a sealer.

I've read on this forum that the original gasket was superseded with a better one. Perhaps the newer gasket shouldn't have sealer? I know that some gaskets are supposed to expand with gas, oil or water, and putting a sealer on them prevents that. Is there a way to look at a gasket and know if it's the type that can have sealer applied?

 

[Evinrude Boater]

Re: powerhead to adapter gasket: sealer?

Welcome to iBoats WestPoint. Good question. I would like to know as well before I get into that stage of reassembly. Mine is 22 years older though.

 

[daselbee]

Re: powerhead to adapter gasket: sealer?

I have been using OMC gasket sealing compound (gorilla snot) on the powerhead to exhaust adapter forever.
I apply it very thinly, just enough to wet it down, and not even enough to really squeeze out when you tighten the bolts. Very Very thin.

Now, I bet I rile some feathers, but throw that Clymers book away.

 

[WestPoint]

Re: powerhead to adapter gasket: sealer?

Much thanks for your advice- I will put a very light coat of sealant as you suggest. I don't have OMC's, but I do have Loctite Aviation gasket sealer 30517, which I understand is equivalent.

OMC's manual also says to apply Loctite 515 gasket eliminator to all powerhead/adapter screw threads. Does anyone recommend something better, or is it ok just use the same sealer as I use on the gasket? I also already have Loctite Threadlocker blue 242, and 3M weatherstrip and gasket adhesive 051135. Would either of these be better?

I pulled the powerhead today and all bolts came out easily. That gasket was really shot. A few posts in this forum advise replacing the bolts- is that really the consensus? Are these the type of bolts that may not be retorqued (TTY or torque to yield bolts), or do they just break down over time?

 

[daselbee]

Re: powerhead to adapter gasket: sealer?

I have always re-used those bolts. The torque spec is not much...only 18-20 ft/lbs., and the bolt diameter is large. I guess the biggest problem is after time, aluminum oxides build up in the threads between bolt and block. Makes it a real iffy situation to assess the quality of the remaining threads in the block after removal. Anything you can put on those threads to reduce the oxidation...I use gorilla snot there too....will help in future disassembly.

I do see in my book that OMC recommends the GelSeal II for those threads (Loctite 515 per your above post.)

I would not use Threadlocker Blue because those threads are already compromised if they have heavy oxidation buildup.