AIR BLEEDS
 

WHEN SHOULD THEY BE CHANGED AND WHAT IF ANY SIGNS ARE THERE TO LET ME KNOW IF I NEED TO GO BIGGER OR SMALLER?

Search for jmarksdragster on here and P.M. him he is very knowledgable on carbs. Maybe he will see this and answer your question. He also has answered some questions in this section if you can't find him with the search.

Curtis

The goal of the main air bleed and emulsion bleeds are to set the fuel curve. If you were to put a tube in a carbs venturi the vacuum or signal created would be linear in proportion to the amount of air flowing through it, however at low air speeds the signal is very low and unstable to meter fuel well. So a secondary venturi is used, the booster, to amplify that signal. The problem is that the signal will no longer be linear. Air bleeds and emulsion is used to correct the fuel curve with a booster, without it the air to fuel ratio would get progressively richer the higher the airflow gets. Most out of the box carbs are somewhat close, some of the newer stuff tends to try to use more emulsion to help atomize the fuel. Improving atomization is fine, but when too much emulsion is used it makes the fuel curve erratic or makes the fuel delivery a low speeds inconsistent and loses power. What are you running for a carb, what engine and car combo is it on?

Two things you can do to help figure it out. Learn to read the plugs correctly and invest in an O2 system like the Innovate LM-2.

im hoping that the small piece of debris i found in the front needle&seat was my problem wont know for sure until next week.