Topic: Location of smallest O ring??

[78cbfun]

Guys I have a brain fart going on.  I bought the 78 550K rebuild kit.  I also have the PD46 carbs.  I know the smallest O ring goes with the air screw spring and washer but where does the other small O ring go?  Does it go round the needle but against the emulsion tube?  Looks like a small countersink on the end of the emulsion tube for an O ring opposite the main jet side.

[kerryb]

Maybe the bowl drain screw?  Or the accelerator pump at bowl seam.

[steeldoncb550]

Guys I have a brain fart going on.  I bought the 78 550K rebuild kit.  I also have the PD46 carbs.  I know the smallest O ring goes with the air screw spring and washer but where does the other small O ring go?  Does it go round the needle but against the emulsion tube?  Looks like a small countersink on the end of the emulsion tube for an O ring opposite the main jet side.

I just rebuilt my carbs and didn’t use one of the smallest ones. I’m really hoping it’s not for the needle seat lol

[90blacknight]

I have a 78 550k and the smallest o-ring was for the bowl drain screw; at least with the kit I got. However it was a bit large, and I ended up using o-rings from my stash.