Just wondering if anyone knows where the vacuum advance is on the Dellorto DHLA40's? At the moment when my car hits 4000 revs and on wards it runs flat and theres no power. im guessing the vacuum advance is the problem.

Vacuum advance should have no effect at 4000 rpm with foot on pedal ... which is one reason why many race cars remove vacuum advance (it only works at part throttle).

Anyways, to find the vacuum advance "port" on the carburetor, examine it carefully. There will be a hose fitting just above the throttle blades (butterflies), it must be on the side of the bore away from the engine.

Note that the idle mixture screw will be between the engine and the throttle blade, but the advance port is between the throttle blade and the air intake (but very very close to the butterfly).

Goto http://www.dellorto.it/ and then go in to the customer area then to documention and d/l the carb manual. there are about 7 d/ls to do but you get the whole manual!!!!

i dont think they have a vacum advance on them, or at least the ones ive got dont. there of an alfa rameo, (never mind the spelling.)

My sets dont have a fitting either. You an run the vacuum advance of the inlet vacuum if you fit a small restrictor pill in the line to stop pulsing on the diaphraghm. It worked ok on my sunny when I had it fitted. Not ideal but worked ok at increassing economy without performance suffering when on cruise throttle.