hey guys just wondering how you adjust the transfer slots on a 650 bg demon? elec choke and vac secondaries.


I know it said to make sure that there is about a .020" space showing on the primaries for engines below 1000rpm idle. however..... is this with the choke on or off? ie if you take yoru carb off, the choke will be ON, but if you pull the leaver and open the flap the butterlies close even more?

and anyone ever have experience with an idle EZE set up? checked the screw and it was all the way in (not open) so I opened it up 1.5 turns and it really doesn't seem to do anything?

cheers

blake

 

Mine doesn't do anything either..lol

 

On Demon and Holley carbs the idle is shared by both the primaries and secondaries. Edelbrocks, AFB's and QJets idle only on the primary side. (secondaries are closed at idle)

You want to balance the carb's curb idle throttle positions of all four barrels so that they are all equaly open and just exposing the tip of the idle fuel transfer slot as you view the throttle plates from the bottom of the carb. (.030 to .050")

Yes the choke should be "open" and the choke's fast idle linkage should not be engaged. (not be holding the throttles partically open beyond the curb idle speed screw)

This throttle reference position with the transfer slots just exposed is the initial setting you want.
The idle eze should be closed. The idle eze allows extra airflow at idle for motors with large rough idle camshafts ( low manifold vacuum) These motors want increased throttle opening ( more airflow at idle. By adding extra airflow thru the idle eze port, the throttles stay in the sweet spot yet the motor gets enough airflow to idle at a good speed.

If you have a small duration camshaft (high manifold vacuum at idle), you won't be using the idle eze. Leave it closed.

Install the carb and warm the motor up to operating temp.
Adjust he idle mixture screws for best idle.
Fine tune the idle speed with the idle speed screw.

If your motor has a big camshaft ( low idle vacuum) you'll want to add idle speed (aiflow) without upsetting the throttle's reference position to the transfer slots ( throttle blade opening) by opening the idle eze port some to get a good idle speed. thethrottles must be open within the sweet spot so that the idle transfer slots are just exposed.
If the transfer slots are not exposed or exposed too much at curb idle the idle will seem rich and wthe motor will not react smoothly at part throttle (just off idle) ( low engine speed ) Engines with big camshaft also will need increased initial ignition timing at idle.

The choke should be open. The choke fast idle linkage should not be engaged.
make sure you have the PCV hooked up to the carb.
If your carb has a 3/8" vacuum port on the base, it is designed to be used with a functional PCV system ( most street carbs) If you don't hook up the PCV, the throttles will end up out of position at idle causing the idle to seem rich and causing a off idle responce problem.

What camshaft are you using? What intake manifold?
High stall converter? stock converter?

Big duration cammed motors need increased initial timing and extra airflow at idle either throu a "idle eze" or some other means. Drilling the primary throttle blades for extra idle airflow is not nessessary. If your motor needs this extra airflow at idle and you donlt have a Demon carb with a "idle eze" there is a simple, better way to get the same thing.

All carbs that have a 3/8" vacuum port (most street carbs) on the carb base are designed to be used with a PCV valve. If you eliminate the PCV, even on a race motor the carb will not idle right.
Even a radical cammed race motor can make good use of a functional PCV system.
A big cammed motor can use two PCV's to get the needed extra airflow or you can adjust the vacuum orifice size inside the PCV valve to get this extra airlfow.
Again, drilling the throttle blades is not nesssessary.

 

What screw is that? Do you mean the idle mixture screws? Or the screws that adjust the transfer slot position?