Hi. I have just replaced my fuel vacuum pipe to a clear one...on idle i have just noticed that at the bottom of the vacuum pipe up to about 10mm away from the carb end i am getting a frothy (assume air bubbles) swirling around inside said pipe? Is that normal or a sign of something simple but obviously wrong, jet too big?, air leak in vacuum pipe etc etc. I havent seen it before as the old pipe was black. Its a dellorto 12 phbn...also are they the same as the phva carb? As thats the settings im using for carb. The clearer pipe on the left is the one in question. Thank you in advance
when idling, it is normal for the vaccum pipe to suck whatever is in the venturi of the carb, especially on a small venturi, as the suction from the barrel is inconsistent, also if its not broke, don't fix it
no need at all, when the engine gains speed and the choke is warmed the pipe will be clear, as there will be a constant draw across the jets.
