r Fig 7 Adjusting Idle Speed Screw t Fig 8 Adjusting Throttle Rod INSTRUMENT Instrument Hook Up 1 Remove distributor vacuum advance hose from R I carburetor spark port tube and plastic cap from L 9 carburetor spark port tube 2 Connect vacuum gauge dwell meter tachometer and timing light NOTE The vacuum gauge must be connected to both carburetor spark port tubes A windshield washer tee makes this possible fig 10 Ignition Dwell 1 Start engine and check ignition dwell If dwell is not within specifications recheck point gap check for wrong point assembly defective or misaligned point worn rubbing block or worn dis tributor cam 2 Check dwell variation Slowly accelerate engine to 1500 rpm and not dwell reading Return engine to idle and note dwell reading If dwell variation exceeds specifications check for worn distributor shaft worn distributor shaft bushing or loose breaker plate ww L Fig 9 Adjusting Accelerator Rod 10 Remove accelerator pull back spring from cross shaft lever hold cross akaft lever in the full throttle position and pull accelerator control rod rearward on vehicles equipped with Powerglide pull through detent and adjust swivel on accelerator control rod until it freely enters hole in cross shaft lever fig 9 Then connect swivel and pull back spring and be sure carburetors return to idle position idle screws against throttle levers 11 Turn idle mixture screws on both carburetors lightly to its seat and back out 1 1 2 turns CHECK OUT CAUTION Accelerate engine at accelerator rol only Do not open throttle by grasping other portions of linkage Set Ignition Timing 1 Adjust timing as required by loosening distributor clamp bolt and rotating distributor body until spe ified timing is indicated at tab fig 11 then tigtiten distributor clamp bolt NOTE Timing should be advanced as far as possible within specifications unless detonation spark knock occurs 2 Check operation of centrifugal advance mechanism by i accelerating engine and watching clockwise adyance movement of timing mark Check Cprburetor Synchronization as Follows 1 Ac lerate engine to 1100 to 1200 rpm and hold steady NOTE A tool to hold engine rpm steady may be manufactured with a small turn buckle and CORVAR SHOP MANUAL