OMC High speed nozzle gaskets

[opposedtwin]

I have a good o-ring replacement for the RD and Bigtwin models (McMaster-Carr 70 BUNA size 201). But I don’t have a replacement o-ring for the other models. Here’s what I have gathered about the jw through FD models:
JW through QD models was #302984 but has superseded to #344037.
FD was 304940 but has also superseded to #344037.

So if all these models now use the same OMC number, isn’t it safe to assume a relacement o-ring would work for all these models? Does anybody have a good lead for a replacement o-ring? What do you guys replace them with? I see the superseded part is still available but I’d rather buy a bag of 100 from McMaster-Carr, etc than pay $5 every time i need one.

[frankr]

Where did you come up with that odd number for FD models? As far as I know they use the same 302984. I think the oring is 1/4" ID x 3/32" thick, but could be wrong. I’m away from home right now.

[seakaye12]

I agree; the price for these cheesy little bits and pieces is absurd; although they are typically included in the carb-kits.

Actually….for the "boss gaskets" or high-speed nozzle gaskets….it’s pretty simple to just knock out your own from cork gasket material sourced from an auto parts store. I use this hollow punch set from Harbor Freight:
https://www.harborfreight.com/9-piece-h … -3838.html

The other thing that annoys me is the price charged for the aluminum expansion plugs. Rather than pay $5.49 from Marine Engine for OMC part #0202310
https://www.marineengine.com/newparts/p … OMC0202310

Why not buy 10 of them here for $4.95?
http://www.carburetion.com/sitesearch.a … or%20Plugs

The other reason for searching out alternatives is that; lets face it…..lots of the parts we typically rely on finding easily now…..will some day in the near future be NLA….

Chuck in Santa Barbara

[vintin]

I was thinking the packing washers were 1/4 X 3/8 inch.

That would make the thickness 1/8 inch.

That is the size O rings I use, anyway.

[frankr]

Yeah, could be 1/8". Put one on the nozzle and lay the carb bowl on without the gasket and see how much space is between the bowl and carb body.

[opposedtwin]

quote FrankR:

Where did you come up with that odd number for FD models? As far as I know they use the same 302984. I think the oring is 1/4" ID x 3/32" thick, but could be wrong. I’m away from home right now.

Frank, that number (#304940) came from my 1957 FD parts catalog.

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[frankr]

OK, I agree, my parts books say the same thing. I don’t know what the reason is.

[Mumbles]

Here’s an old thread about O ring replacements for the boss gasket.

viewtopic.php?f=2&t=2516#start_here

[vintin]

I’m confused and was talking about the high speed needle packing washers. Sorry about that.

[opposedtwin]

quote Mumbles:

Here’s an old thread about O ring replacements for the boss gasket.

viewtopic.php?f=2&t=2516#start_here

Mumbles, I think that thread gives the number for the o-rings that are replacements for the RD and Bigtwin models. I’m looking for rings for the other models like JW-FD.

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