I am running two 45 webers on a 2 litre pinto. One of the carbs has a different air flow through its two barrels. Is there anyway of adjusting it so that the two barrels are sucking in the same amount of air?


I am also getting a backfire through the exhast when taking my foot off the accelerator pedal after accelerating. Am I right in thinking that the mixture is too rich? The timing has been checked and is spot on.

Any help is most appreciated

Something is wrong it is possible the throttle spindle is twisted but unless the carb has had a very badly designed throttle linkage this is unlikely --- first thing to do is check the cylinder is actually firing then if nothing found the valve clearances, if still nothing do a compresion test.

Weber manual says-
turn the throttle adjustment screw until the flow indicator is midway . or if you are using a length of hose - that the "hiss" is the same as the other carb

hope it helps

Check for air leaks, between carb and manifold, manifold and head.
Also check the spindle bearing for wear.

I've seen DCOEs with twisted spindles, caused by using very strong return springs on the opposite end of the spindle to the linkage.

check that you have the same chokes in both carbs. I bought a'pair' that had different chokes!

Are you getting a real backfire or just popping on overrun? the latter is pretty normal with webbers.

Out of interest where did you get your timing settings? if you are using different carbs and exhaust timing may ned to advance a bit as you have better flow through.

Caber

Twisted spindles are pretty common on competition cars where over zealous scrutineers insist on additional throttle return springs on the opposite end of the spindle to the throttle cable.

You can sometimes see the difference in the opening of the butterfly.

Wyn