O-Ring replacement for the needle packing washers?

[mr-asa]

I think I have that same box, Wedgie. I don’t know if they are Buna washers though.

I’ve got two motors currently running Buna o-rings instead of the ones that come in the pack. I like them and haven’t had any issues so far, I just wanted to try it with a couple others and run them till I had issues.

[mr-asa]

quote cajuncook1:

Slow and high speed packing (dimensions from Sierra washer packing 18-7106 and OMC 0307583

Dimension

OD 9.5mm or 0.375 inches 3/8 inch

ID 6.43mm or 0.253inches 1/4 inch

thickness 1.6mm and 0.063inches 1/16 inch

Based on these dimensions, the dash number for an o-ring to fit the fuel metering needles is 010, just in case anyone is looking.
http://www.mcmaster.com/#9452k18/=yl07uv

[Mumbles]

Shake the moths off your wallet and buy the proper packing washers.

If O rings worked reliaby, I’m sure OMC would have used them in their motors.

[jim-moffatt]

I have used o-rings many times. They work well. The adjustment is a little sticky and springy but that really isnt a problem.

[burnt-clutch]

Would these be the same packing used on the needles that the TN and HD series motors use? I think I’m missing the packing on my high speed needle.
-Karl

[frankr]

I may be wrong, but I don’t remember a TN as having any packing on the high speed needle. Probably has something on the slow speed needle though. But I admitted I may be wrong.

[aquasonic]

quote FrankR:

I may be wrong, but I don’t remember a TN as having any packing on the high speed needle. Probably has something on the slow speed needle though. But I admitted I may be wrong.

That’s right. There is no packing on the high speed needle assembly for the HD, TD, and TN models. The low speed needle, however, calls for two packing washers. They are of a smaller size than the ones used later in non-rotary valve motors.

[lotec]

I’ve tried neoprene and viton o-rings as the packing and had difficulty getting the gland nut tension so its tight enough it won’t rattle off, too tight the needle won’t turn. Plus our wonderful ethanol gas eats up the high-speed ones in no time. The fiber ones in the OE kit work fine, but I do find they swell with use/shrink with dis-use. (Every spring the knobs twirl on first start up – 10 minutes later they are nice and stiff) The old manuals suggested soaking them in kero before installation so you can get the gland nut tension correct from the get-go.

I echo the comments above – always replace them where needed when a new motor comes to me, the old ones are almost always guaranteed to fail. It’s just one small fix, not doing it can lead to some funky running conditions.

[reivertom]

Could the graphite plumbers packing be a good substitute for these type applications? I think it should be "gas proof" and it packs great when I use it to pack faucet stems. It would be great if it works because it’s cheap and can be made to fit any size.

[eviltwin]

I read you could make them with white cotton string wrapped around the needle and coated with bar soap and graphite. Tried it on my Elto, seemed to work. Not sure about where it seats.
I also recall seeing that type of material in my fuel shut off valve. Got a pack of o rings at the auto parts store and found one to fit. No leaks there.

[Author]

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