Gas comes out one dual SU vent at high-er rpms

[spudly13]

I Have a 71 datsun 510 with a stock l16, stock fuel pump. my most recent problem is gas coming out of the vent on the top of one dual Su at high rpms

 

Wondering what causes it before i go taking it apart!

[ggzilla]

There is only one thing that causes it -- the fuel level is incorrect. You can probably fix it by adjusting the float level, but the float also might have a hole it it. New floats are $17 from Nissan. Or it could be a partially leaking needle-and-set for the float, so inspect that carefully. They rarely go bad, but if they do it's the same one used by downdraft Hitachis.

[spudly13]

Sweet, ill take it apart and inspect everything then try adjusting the float level

[Sealik]

They rarely go bad, but if they do it's the same one used by downdraft Hitachis.

 

Hmmmm...good to know.

Are the floats larger in the 46s?

[ggzilla]

Yes, or at least they are different. They don't interchange with 38mm floats.