67 B-body
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- Jun 13, 2010
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Has anyone else experienced a lean idle mixture on a Holley DP carb?
I can't seem to get mine rich enough at idle...... My carb is older, so it only has idle mixture screws on the front metering plate, and the engine wont idle without the screws being 5 1/2 turns out! At this point, I believe it is maxed out and any further turning would do nothing. Spraying carb cleaner through the idle screw ports "with screws removed" shows cleaner coming out of the idle transfer slots.... The throttle blades are not open past the transfer slots.... The rear set of blades seem to be in the correct position at idle....
Before adding the 50cc pump, it would stumble at first throttle if you hit it quickly. That is now resolved... I added two sizes larger jets front and back to fix a little lean condition cruising and WOT... If I hit the accel pump arm at idle, it picks up RPM indicating a lean mixture... Strangest damn thing I ever seen....:angry7:
Other than idle mixture, it works like a champ! Very crisp, strong pulling, doesn't lean out at top RPM anymore.....
I can't seem to get mine rich enough at idle...... My carb is older, so it only has idle mixture screws on the front metering plate, and the engine wont idle without the screws being 5 1/2 turns out! At this point, I believe it is maxed out and any further turning would do nothing. Spraying carb cleaner through the idle screw ports "with screws removed" shows cleaner coming out of the idle transfer slots.... The throttle blades are not open past the transfer slots.... The rear set of blades seem to be in the correct position at idle....
Before adding the 50cc pump, it would stumble at first throttle if you hit it quickly. That is now resolved... I added two sizes larger jets front and back to fix a little lean condition cruising and WOT... If I hit the accel pump arm at idle, it picks up RPM indicating a lean mixture... Strangest damn thing I ever seen....:angry7:
Other than idle mixture, it works like a champ! Very crisp, strong pulling, doesn't lean out at top RPM anymore.....