hi, i have a datsun a15 with dellorto dlha40 carburetors

known mods:
~porting on the inlets, a bit bigger than a12gx ports
~4-1 headers
~the carburetors

it seems to be over fueling, sooting the plugs and blowing a bit of black smoke.

does anyone have a similar setup to this and what jets are you using and are they suitable? If you have an air-to-fuel ratio reading that would be very handy.

thanks very much

135 main 190 air would be a good starting spot with such small chokes. Also make sure your float level is spot on.

On wide band these carbs run richer than you would think, idle around mid 13's WOT in the mid 11's, any leaner than that and mine would mess about, on cruize should would hover between 13.5 and 14.1

just an update:

mains: 130
emulsion tube: 7772.7
air: 180
Idle: 57
jump: 38
venturi: 32mm