Topic: petcock mystery

[rupaulpierce]

This o-ring should either be buna-n or viton. If it's a typical o-run not meant for file then it'll swell and not seal and over time will disintegrate. Just making sure you chose the right o-ring.

The correct o-ring is 23mm diameter, but what thickness in mm?

[DaveBarbier]

This o-ring should either be buna-n or viton. If it's a typical o-run not meant for file then it'll swell and not seal and over time will disintegrate. Just making sure you chose the right o-ring.

The correct o-ring is 23mm diameter, but what thickness in mm?

You're talking about an o-ring that seals against the tank bung, right? I actually don't think an o-ring is good for this application. O-rings are designed to live in a groove and only be compressed a little bit, like 10-30%. Having an o-ring here will squish it completely which may tear it or at least shift it. I believe a rubber or Teflon washer is best, something more rigid with a flat profile.

[rupaulpierce]

It's an o-ring, you must be thinking about a different petcock design?

Part #10: http://www.cmsnl.com/honda-cb350f1-four-1974-usa_model434/partslist/F++11.html#results

[rupaulpierce]

23mm ID x 2mm

http://4into1.com/genuine-honda-petcock-body-o-ring-16997-273-006-cb350f-cb500k-cb750k/

[DaveBarbier]

It's an o-ring, you must be thinking about a different petcock design?

Part #10: http://www.cmsnl.com/honda-cb350f1-four-1974-usa_model434/partslist/F++11.html#results

Yup, you're completely right, I was thinking of the other style that's threaded on with a large nut

Carry on!

[rupaulpierce]

Do i even need to worry about Viton with this style?

[DaveBarbier]

It's sealing gas so it needs to be fuel resistant. Buna-n also resists fuel. Viton has a higher heat resistance which I doubt you need here.