Carb Question

[V8Coupe]

I'm trying to set my idle mixture screws on a 650 Edelbrock, normally a simple procedure. One screw reaches highest idle at just less than 1 turn out. The other takes 2.5 turns to reach highest idle. I removed the screws and inserted the correct size drill bit, all the way, to check for an obstruction, there was none, and both had the exact same bore size. Intake manifold is Performer dual plane. The exhaust stinks to high heaven at idle, but I cant seem to correct it with the mixture screws. There's no problem with the choke, and the carb is new. Might there be another problem on one side of the engine causing this. I recently did a compression test and had 170 to 175 all the way around.

 

[techg8]

a vacuum leak on one side could contribute to this
Lean exhaust has a sharp stink/smell to it.

what vacuum readings are you seeing at what idle rpms? is your engine stock or cammed?

 

[Blake442]

Unfortunately it is not uncommon for Edelbrock carbs to be junk right out of the box.
Keep that in mind before you dig yourself too deep...

I had one on my Cadillac when the motor was rebuilt.
Ran perfect for about 50 miles, then out of the blue it started running so bad I almost didn't make it home.
No amount of tuning would correct it so I sent it back and rebuilt my original carb and it has run perfect ever since.
I'll never buy another and wouldn't recommend them to anyone.

 

[Fox80]

Unfortunately it is not uncommon for Edelbrock carbs to be junk right out of the box.
Keep that in mind before you dig yourself too deep...

I had one on my Cadillac when the motor was rebuilt.
Ran perfect for about 50 miles, then out of the blue it started running so bad I almost didn't make it home.
No amount of tuning would correct it so I sent it back and rebuilt my original carb and it has run perfect ever since.
I'll never buy another and wouldn't recommend them to anyone.

Could not agree more,that design was junk when Chrysler used it and still is today, sent three of them back over the years, very nice people to deal with, they seem well aware the carbs suck and are more than willing to send you another one. Only two carbs in my mind whatever came on it if your a purest and a Holley if you want it actually run, try and borrow a carb before you open up a can if worms

 

[olds307 and 403]

How is your mileage? Any driving issues? How did the plugs look? They should be light to medium brown on the electrodes. What are your motor specs? It could be jetted too rich for your car. I would trade it in for a new Street Demon.

 

[V8Coupe]

Thanks to all for your input. In answer to your questions, yes the car does have a cam. Its a Comp XE262, 218 & 224 @.50, 462 & 469 lift, LS 110, ICL 106.
Heads are Vortec.
Pistons are stock dished.
Vacuum is 15 @ 700 rpm.
Timing is set at 12 degrees.
Engine is fully heat soaked before tuning.
Other than the huge difference between the turns of the idle mixture screws, and the smelly exhaust at idle, it runs flawlessly, and quite efficently.
I'm at a loss as to why I cant tune this condition with the idle mixture screws.