twin 502's that run great untill i back out of it. one likes to die if i back out quickly after running wot for awhile. a friend (marine mechanic) isnt sure what the cause is.

holley 750 dbl p.
stock bbc

can anyone give me some ideas?

thanks ,
lotoparty

Check to make sure you have enough fuel pressure and the float level is set correctly. Also make sure both butterflies are adjusted to the same opening size. If this checks O.K. I would check for a vacuum leak and make sure idle jet circuit is working properly.

if i didnt have enough fuel pressure wouldnt it cough or die "while" i was at wot instead of afterwards?

lotoparty:

Can you make the problem happen by just reving up that engine and letting out of the throttle ? Most likely your problem is in the carburetor. To die when you back out of the throttle likes this the motor is most likely pulling too much fuel through this carburetor. Make sure your float levels are set right, and you do not have too much fuel pressure. If the problem continues remove the carb, and set your butterflys so both the primary, and secondary sides are open the same amount. If at this point the problem still persists swap carbs from engine to engine to see if the problem follows the carb, or it's something else. Your carburetor may be in need of a rebuild.

Doug