Drain plug gasket -- will an o-ring work ok?

cmjust0

Seaman
Joined
Aug 14, 2002
Messages
52
Hey guys. I have a 1992 Force 70HP. I had a fairly serious water intrusion into the lower unit recently (still working that out) and something I noticed was that my drain plug gasket/seal/washer/whatever was pretty much shot. It was the paper crush gasket type, and I'm fairly certain that if I'd rubbed it between my fingers, it would have disintigrated.

The other day I was in a Tractor Supply Co. store and happened past their o-rings. A package of o-rings caught my eye that looked to be just about the same size as my drain plug gasket. I was curious and they were only $2, and were spec'd for water, grease, oil, etc., so I bought them on a lark. When I got them home, I'll be daggone if they're not just about *exactly* the same size as the crush gasket. Same outer diameter and same thickness.. I had to pull the drain plug anyway, so I went ahead and stuck one on the drain plug just to see if it would go up in the inset without hanging over and having plug itself pinching it in half of something like that...it fit perfectly. I tightened it down and it got really snug.. I pulled it again right away to inspect it for damage, and it was actually kinda difficult to get back out.. The plug itself seemed tighter in the hole, and I had to hook the o-ring with a smaller screwdriver to get it back out.. And it didn't look like it was marred or anything like that from installing it and tightening the plug on top of it.

I know the *actual* gaskets are cheap enough that nobody should really be looking for replacements, but my local merc dealer gets $1/ea out of them and, like I said, these things were $2 for a 10 or 15 pack.. Plus, my merc dealer is about 45mi from my house..

My question is whether there's any reason *not* to run an o-ring instead of a bona-fide Quicksilver gasket/crush washer?
 

BuzzStPoint

Lieutenant Junior Grade
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May 27, 2009
Messages
1,003
Re: Drain plug gasket -- will an o-ring work ok?

Only thing I would worry about with orings is the dry out and cracking.
I buy my plug seal at CarQuest. They have 2 types, they have a nylon and fiberous. A few guys seem to not like the nylon because of the cracking issue again, so i picked up a few of the paper fiberous material. They were cheap so I dont even remember how much I spent on it.
 

cmjust0

Seaman
Joined
Aug 14, 2002
Messages
52
Re: Drain plug gasket -- will an o-ring work ok?

Well, after what I've been through with water intrusion issues, I'd say I'll be just nervous enough in the future to check it every few trips out anyway (if not *every* trip), so I don't think I'd ever let one go long enough to dry out or crack.. Watching water *pour* out the drain hole made me a little gunshy, what can I say...lol! Good tip on the CarQuest seals, though! I'll have to take one of those o-rings into an auto parts store and see if I can find something to match.. Seems to me that what I've seen in AutoZone so far have been considerably larger than what we need for lower unit plugs, but maybe that's just an AutoZone thing.. I'll look in Advance Auto, O'Reilly, Napa, and KOI for sure, but I don't think I have a CarQuest handy.. :-/
 

wickware

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Jun 20, 2009
Messages
1,286
Re: Drain plug gasket -- will an o-ring work ok?

I d/n see an ?O? Ring taking good torque pressure w/o damage w/o a grove etc to restrict it. As Frank said, ?Things Are Designed For A Purpose?. I would have to go with the OEM nylon etc or a copper crush washer. Who know the actual grade of an after market ?O? Ring? I had one to melt in a floor jack in the 70s and that was my last after market ?O? Ring lesson. Take Care! jow
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
18,071
Re: Drain plug gasket -- will an o-ring work ok?

NO It needs a fiber washer.The mating surfaces aren't set for o-rings.They sell fiber gasket at all marine stores.Jap motors need a smaller gasket.
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: Drain plug gasket -- will an o-ring work ok?

There are outboards that use "O" rings to seal the vent and drain plugs, BUT those plugs are specially contoured for "O" rings.

The flat surface plugs must have a new, crushable gasket every time they are removed.
 

cmjust0

Seaman
Joined
Aug 14, 2002
Messages
52
Re: Drain plug gasket -- will an o-ring work ok?

Okey dokey.. That's why I asked. :) I'll run to the merc dealer and grab some of the gaskets next time I'm out that way. Or, better yet...does anybody know of a reliable internet parts supplier where I can order some cheaper than $1/ea? I'm looking for a good parts website anyway...every one I've seen so far (aside from iBoats, I guess) seems a little, um....shady? lol
 
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