C-2 Carb Question.....

[Larry S.]

My 1966 BB 4-speed has a Holley #3247 carburetor that has been recently rebuilt and the engine seems to run fine. I would like to know if there is some way to test that the secondaries are opening properly on full throttle. If I rev it up quickly while parked with the hood open, I dont see them open at all. Obviously I dont want to hold the throttle wide open without a load on the engine. Any ideas on how to check this out, or should they open immediately?
Thanks for any thoughts you may have.

[Mike G.]

Re: C-2 Carb Question.....

My 2818 Holley won't open the secondaries unles the car is under load, so I used a piece of clay under the linkage arm as a "witness plate" to confirm movement during road testing.

[Jack H.]

Re: C-2 Carb Question.....

What you observe is par for the course, the engine needs to loaded and revs sustained to crack the secondaries open. If you want to verify they're opening, take the car for a drive and stand on it...

I guarantee you, the engine will NOT climb above 4000 RPM without the assistance of the secondaries opening to sustain air/fuel mixture at the flow rate needed for higher revs!

[Larry S.]

Re: C-2 Carb Question.....

Thanks Jack and Mike for that valuable information. It is great to be able to get such immediate help from others who have "been there".

[John H.]

Re: C-2 Carb Question.....

On the passenger side of the secondary shaft, you'll find a lever that bottoms out on the carb base as a wide-open stop. As Clem has noted in the past, if you put a small gob of grease on the carb base and then take it out and romp on it through 2nd and 3rd gear, you'll find grease transferred to the lever if the secondaries opened all the way.

[Larry S.]

Re: C-2 Carb Question.....

Thanks John, I'll try the grease.