Ok heres the scoop, 12a half-bridge-45dcoe carb-open race exhaust-red holley fuel pump. I rebuilt this motor myself and it fired right up and sounds great. But when the engine is under load I get some "popping/backfiring" noises coming threw the carb. Im not to sure where to set the timing either. The noise sounds like detonation but im not really sure. One more thing the engine makes alot of power untill the popping starts then it just seams to lose poweruntill I back off the gas.
so answer these q's.
-where to set timing?
-what fuel pressure should I be running?
-Is this noise detonation?
-can this carb really not handle this motor?

 

I don't think it's detonation.

Does the popping occur at a certain RPM?

 

No not at any certain rpm, just when the engine is under load. I have this posted in the first gen forum also and got a couple of suggestions.
-fuel pressure?
-timing?
-carb jet size?
Does any one know where any of these adjustments should be set at?.
Remember its only a small half bridge.

 

start out looking at the timing and vacuum advance

 

The timing is set a 5 leading and 20 trailing, just like it was on my stock port. Could the dist. be ******* up internally?, and not advancing?. Heres a little more info.
-my elevation is like 5000ft in Colorado
-the main gas jets are 180
-air correction jets are 175
-idle jets are 65
-accle. pump jets are 65
its a 45DCOE weber, 12a halfbridge. any one know what jets will make this engine run without popping through the carb?.

 

2 more things I forgot
-fuel pressure is at 4.5 pounds
-and the emulsion tubes are F11