Do you use Loctite on your lower unit bolts?

Scode68

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Do you use Loctite on your lower unit bolts? The copy of the manual says to use a kind that is no longer made but there isn't any evidence of there being any on the bolts. I've had this motor since new from 1995.
Same is called out for the water pump also but it looks like there might have been some white on there but no red, blue or green that I'm familiar with.

20hp OG113 motor
 

Scode68

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I don't think 271 is the answer even though the manual says so. I'm going to go with the Loctite blue cause I use this motor in salt water.
I don't think it matters but I'm installing the Bay Manufacturing's short to long shaft conversion. It has SS studs that are used instead of the bolts.
 
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Lou C

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Nov 10, 2002
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On lower units I’ve used Evinrude gasket sealer on bolt threads this keeps water out and reduces the chance of seizing up even in salt water. I have an OMC Cobra that lives in salt water 5 months out of the year & the bolts for the anodes come right out when the threads are coated with this stuff…
 

Jeff J

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What does the manual actually say? I don’t have a Mercury manual but I know the Suzuki manual calls for thread sealer instead of thread locker in those places. Fairly certain Yamaha does too. The only “certified” boat mechanic I watched do an impeller didn’t put anything on the threads.
 

Lou C

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OMC said to use their gasket sealer in their shop manuals.
 

Scode68

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I don't have the manual here at work but the parts catalog says to use Loctite 271. That is the red one for permanent installations.
 

Jeff J

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I don't have the manual here at work but the parts catalog says to use Loctite 271. That is the red one for permanent installations.
My experience with red loctite is that it isn’t uncommon for it to take heat, as in torch, to break it loose so I am with you on your choice not to use it. I wonder if that parts manual has a misprint. It would be nice to hear from a certified Mercury mechanic on this.
 

Lou C

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Agreed I can’t imagine why they would loctite those bolts on with the red when the blue would suffice, furthermore lower unit bolts just don’t back out, in fact the main problem is seizing due to salt water intrusion on the threads. A gasket sealer like Merc Perfect Seal, Evinrude Gasket Sealer or even Permatex Aviation will do that job nicely.
 

jimmbo

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A gasket sealer like Merc Perfect Seal, Evinrude Gasket Sealer or even Permatex Aviation will do that job nicely.
Edelbrock Gasgacinch is pretty much the same stuff, or it used to be
 

jheron

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I use marine grease for the bolts my lower ends, or any grease for that matter.
Cheers,
jon
 
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