do I have to pre tune the carb or jes slap her on?
it's a 390 specific carb,c5af an.


Fe power

 

Hi,

I need a little more info. Is this a new carb? rebuilt carb? other? If rebuilt then you would have to adjust the float level in the bowel(s). ALso the idle screws, I would start off by screwing them all the way in and then backing out 1 1/2 to 2 turns.

Post more info.
Lee

 

the carb is a remanufacteered one. its on my
work table waiting to be fiddled with.
How do I go about adjusting float bowl levels
its from a 64 maurader 480cfm 4v vacuum secondarys.

Fe power

 

Hi,

If the carb is a Holley you will find on top of the bowels a lock nut/screw. This is the float adjust. Screw it in to lower the fuel level, out to raise. On the side of the bowel look for a screw plug. The idea is to install the carb and adjust the screw till gas just trickles out the plug. It's a trial and error adjustment. Adjust screw, crank engine and let run a minute, shut off engine, unscrew side plug and check level, repeat. Some carbs have a sight glass on the bowel for easy viewing. I know on some other types of carbs you have to get inside the bowel and bend the metal float rod to adjust the level.

As for the idle screws there should be 2 screws located near the base of the carb. One on each side usually towards the front. Gently screw in all the way then back out 1 1/2 to 2 turns.

You will also need to adjust the choke. If it has electric choke there should be a large (usually black) plastic looking cap on the passenger side with a wire attached to it. It should be held down with a metal ring with 3 screws. Loosen the screws and rotate the cap to adjust. Work the throttle to the wide open position and back to closed. This will allow the choke to activate. Adjust so that the choke plate on top of the front 2 barrels are almost fully closed. With the carb installed and the engine up to temp make sure the choke plates are all the way open. Adjust as required.

Hope this helps,
Lee