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Message |
    
art oberst
New member
Username: itaxitoo
Post Number: 1
Registered: 07-2009
| | Posted on Tuesday, July 07, 2009 - 06:55 pm: | 
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I have a 1990 mariner magnum 40 HP 4 cyclinder serial # oc226863. I am replacing the power head gasket and need the torque specifications. Also this is the 2 time in 6 years that this gasket is being replaced do I need any gasket sealer?
What is the expected life of this gasket - the boat does not get more than 10 hours of use per year - any advise would be appreicated. |
Fastjeff
Senior Member
Username: fastjeff
Post Number: 6206
Registered: 09-2003
| | Posted on Tuesday, July 07, 2009 - 07:52 pm: |
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Do use some silicone. Tighten them up 'til they are nice and tight. Run the motor, then re tighten. And forget about using that torque wrench! Threads need to be perfectly clean and lubricated to mean anything--impossible in this case. The mere act or sliding the studs down into the tower coats the threads with aluminum.
Jeff |
Graham Lamb
Senior Member
Username: galamb
Post Number: 5559
Registered: 05-2007
| | Posted on Tuesday, July 07, 2009 - 08:57 pm: |
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10 foot pounds is enough - base gasket could last a year or practically forever.
I usually replace it every 4th year when I throw in a complete waterpump kit - not because it's really required, but I pull the powerhead to get a look at the the watertube seal at the powerhead base and that destroys the gasket... |
art oberst
New member
Username: itaxitoo
Post Number: 2
Registered: 07-2009
| | Posted on Tuesday, July 07, 2009 - 09:16 pm: |
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By silicone are you referring to a marine silicone caulk or is there a special marine silicone gasket sealer?
I was also reading some other posts and it appears that mariner was made by a number of different manufacturer's. What can be learned from the above serial #?
Thanks for all your help, I really apppreciate.
Between my neighbor who repairs tons on lawnmowers and myself, we should be able to handle the job. |
Graham Lamb
Senior Member
Username: galamb
Post Number: 5564
Registered: 05-2007
| | Posted on Tuesday, July 07, 2009 - 09:43 pm: |
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I put my base gaskets on either "dry" or use OMC's gasket sealer (just because that's what I have around) - there are a number of products on the market that work just fine.
Your serial indicates it is a Merc built Mariner, but used the Yami designed and built "headless" split-block design (standard on many Merc motors).
The gears as well almost certainly came from Yamaha.
But this should not be confused with the 100% Yamaha built Mariners, which this is not... |
