Dual Weber 40 IDF Brevettato Carb Synch Issue

[choirman]

I have a set of Italian Brevettato Weber 40 Carbs that I picked up and my mechanic cleaned them thoroughly in his ultrasonic cleaner and rebuilt them with a new rebuild kit. We’ve got them on a 1904 and the engine runs, but when we put a synch gauge on them and test at each velocity stack, one side is pulling at 3-5 kg/h and the other side is pulling air at 10-12 kg/h and we just can’t seem to get them to match. Another old school mechanic buddy said that I probably have a dead carb and to just order a new one. I am replacing a single working Redline Weber 40 and I’m thinking I should buy a new Redline to match the one I have and run the Redlines. Anybody know what may cause the Brevettato’s from syncing (or maybe thats’s close enough?) or have a thought about just going with ordering a new Redline?

Also - we measured the temps coming right off the header and the temps on the low side we’re just above 100 F but the strong side had temps several hundred degrees higher. We switched the carbs to the other side and the temps were the same on the reverse side.

[Starbucket]

First make sure the Linkage is synced by lightly holding a drinking straw on each carb butterfly and have a helper slowly press on gas peddle and feel for both carbs to open at exactly the same time, then use your gage.

[choirman]

We had the linkage off and were testing at idle.

[VW_Jimbo]

Did you set the throttle plates exactly the same?
_________________
Jimbo

There is never enough time to do it right the first time, but all the time necessary the second time!

[Starbucket]

Check the manifold surfaces for flatness with straight edge or check for leaks with "sure start" sprayed near carb base at idle, listen for rpm increase for leak.