Where can I get viton o-rings for carb rebuild

[koolaid_kid]

Got the o-rings today. The 3.0mm ID, width 1.5 mm worked fine on the air screw. The 3.5mm ID, width 1.5 mm were too narrow in width for the drain screw, although the ID was correct. Now that I have new o-rings, I figured out how to measure them with my caliper, and I determined that I need 3.5 ID and width of 1.8 mm. McMaster-Carr does not list that size, so I sent them a request via email. Where else can I look?

 

[Nessism]

What's the problem with the drain screw O-rings? Is the OD too small thus the need for a thicker O-ring?

BTW, a -007 O-ring has an ID of 3.68mm and width of 1.78mm

Don't forget to check the dash number sizes as well.

 

[koolaid_kid]

What's the problem with the drain screw O-rings? Is the OD too small thus the need for a thicker O-ring?

Yes. Of course, since they are related, you could say the diameter is too thin so the OD is too small...
I've looked at American sizes, a -007 looks close. Robert Barr suggested that I also try a -006.
Edit - the -006 is too small. I just triple checked the screw, it measures 4.10mm, so that still gives me a bit of stretch. Sigh.

 

[Nessism]

Yes. Of course, since they are related, you could say the diameter is too thin so the OD is too small...
I've looked at American sizes, a -007 looks close. Robert Barr suggested that I also try a -006.
Edit - the -006 is too small. I just triple checked the screw, it measures 4.10mm, so that still gives me a bit of stretch. Sigh.

Why not -007?

 

[koolaid_kid]

Order placed for -007s. They should be fine. I had looked at them earlier and asked him if he had them in stock, but he did not.
Not sure why he suggested the -006s.