Topic: '77 CB550F, 069A float valve base o-ring size?

[fastbroshi]

  Does anyone know what size o-ring this part is?  This o-ring goes around the brass piece that sits in the carb, that the needle valve (correct term?) goes in.  I know for a fact they come in the carb kits but I don't want to buy the whole kit just for that one. 
  I've got a carb that just won't quit overflowing.  I've checked:

1.  Brass overflow tube for cracks, switched with another known good bowl
2.  checked float height, switched with another just for kicks
3.  switched needle valves with another

And it still overflows like crazy.  If I take the bowl off to observe flow, I can manually shut off the fuel.  My only guess now is this o-ring, as I can see some movement in this brass part, as if the current o-ring has shrunk and may be allowing some movement.

[Deltarider]

5,7x1,3 mm
Source: an old CB500 Parts List p.51 where these parts still had their individual partnumber. This one is - hard to read - 16171-551-004. http://www.honda4fun.com/pdf_parts_list/pdf_spac500/CB500-71/CB500-71_2.pdf
CB550 O-rings are the same. In Europe the genuine part costs around € 3,-. http://www.cmsnl.com/products/o-ring-57x13_16171551004/
Although I personally would not use Keyster brass parts, maybe their gaskets are OK. Such a gasket set could be more economic. Others may chime in on the quality.

[fastbroshi]

Thanks a bunch for the info Delta.  I'll see about ordering some.  Local Honda dealer says their discontinued :/.   Looks like Z1Enterprises has a pack of 25 for $18, I may just go for that. 

On a side note, damn....does gasoline these days go bad fast or what?  I have some that I poured in my auxilliary fuel tank from the container that I use for lawnmowers and such.  And through the course of my troubleshooting I've been draining the bowls, pouring the gas back into the aux container...and it's been looking milky as hell, leaving a bit of residue on the bowls as well.   This gas is relatively fresh, I'd say 3 months old, max.   

Is it unreasonable to think it might stay fresh longer? 

[Deltarider]

Gasoline is far from what it was in the 70s. American gasoline never had impressive quality and I've heard things got worse. The sugarbarons form a strong lobby in Washington and after adding sugar to practically all Foods and Drinks (resulting in an epidemic of obesity that is unprecedented), it's now gasolines turn to be 'enriched' with corn syrup. There are products in the market that stabilizes fuel like for hibernation however.