500 rpm automatic transmission in drive and synchromesh in neutral hand brake applied Adjust idle mixture screws fig 7 10 on both carburetors to obtain peak steady vacuum at given idle speed rl IDLE MIXTURE ADJUSTMENT V l Fig 7 10 Idle Mixture Adjustment f Remove vacuum gauge and close adapter as required for given transmission model 4 Carburetor Balance Vacuum Check a Remove distributor vacuum advance hose from right hand carburetor and plastic cap from left hand carburetor spark port adapter tubes fig 7 11 b Connect vacuum gauge to adapter tube of each carburetor best results will be obtained using 2 equally calibrated gauges c Move accelerator lever fig 7 9 to obtain 1200 rpm all transmissions in neutral d Check vacuum readings at each carburetor and note difference If difference is one inch or less the carburetors are satisfactorily synchronized If difference is more than one inch return engine to idle and adjust left carburetor throttle rod one turn up to increase left carburetor vacuum and down to decrease and recheck carburetor vacuum difference at 1200 rpm Make adjustment by disconnecting rod at cross shaft end and rotating in swivel Repeat adjustment until difference is within one inch of vacuum I NOTE It is preferable to have higher reading on right carburetor distributor advance side CAUTION When making linkage adjust menta accelerate engine by moving accelerator rod only fig 7 9 Do not open l 4 7 SPARK PORT VACUUM CONNECTION t Fig 7 11 Spark Port Vacuum Connections throttle by grasping other portions of linkage or this may upset geometry and synchronization e Remove vacuum gauge or gauges replace distributor advance hose on spark port adapter tube of right carburetor and plastic cap on left carburetor spark port adapter tube 5 Final Curb Idle Speed and Mixture Adjustment Check NOTE Always make final idle speed mixture adjustment with air cleaners installed a Replace air cleaners b Reconnect vacuum gauge to vacuum balance tube adapter c Read vacuum at idle speed of 500 rpm If necessary adjust curb idle speed and mixture screws to highest steady vacuum reading between 14 18 inches CAUTION Any necessary adjustment must be duplicated at each carburetor 6 Recheck Fast Idle Setting as Outlined in Step 1 C This setting depends upon final curb idle 500 rpm setting CHOKE ADJUSTMENT 1 With the slide fig 7 12 1 4 from the rear of the mounting bracket and choke knob on dashboard out approximately 1 g tighten the slide screw onto main choke cable wire CORV IR SHOP MANUAL