Fig 10 Vacuum Gauge Adopter and Turnbuckle hooks fig 10 When this tool is installed between the accelerator rod and fuel line the rpm can be adjusted by turning turnbuckle 2 With rpm set to 1100 to 1200 and steady note vacuum reading Pinch shut vacuum gauge hose to R H carburetor and note vacuum reading If vacuum decreases return engine to idle and lengthen throttle rod one turn on L H carburetor then recheck If vacuum increases return engine to idle and shorten throttle rod one turn on L H carburetor then recheck If vacuum remains steady tl open hose to R H carburetor and pinch shut vacuum gauge hose to L H carburetor Vacuum should remain steady fl 3 Disconnect vacuum gauge from spark port tubes and reinstall distributor vacuum advance hose on R H carburetor and plastic cap on L H carburetor Vacuum Advance Check operation of vacuum advance by accelerating engine and watching movement of vacuum advance arm Idle Speed and Mixture Adjustment 1 Disconnect choke diaphragm hoses from both carburetor bases and connect vacuum gauge at these locations 2 Adjust idle speed duplicate adjustment on both carburetors to obtain specified engine idle 3 Adjust idle mixture screws on both carburetors to obtain peak steady vacuum at specified idle speed Adjust Fast Idle Cam Clearance Fig 12 1 Stop engine 2 With throttle lever on next to the highest step of fast idle cam bend tang to obtain 078 clearance between idle speed screw and throttle lever Adjust Vacuum Diaphragm Fig 13 1 Hold choke valve closed with a rubber band 2 Hold vacuum diaphragm arm squarely against diaphragm Y x SL CHECK REFERENCE Fig 11 Ignition Timing 3 Measure clearance between lower edge of choke valve and wall of bowl cover Clearance should be 180 to 195 4 If necessary to adjust disconnect and bend diaphragm link 5 At this setting throttle lever fast idle tang should rest on next to the highest step of fast idle cam If not adjust by bending outer choke shaft lever tang Adjust Vapor Vent Fig 14 ie vent should just start opening when idle screw is on high step of fast idle cam The valve will then be open at idle setting If necessary adjust by bending throttle lever tang NOTE It is hard to see this valve when carburetor is installed A mirror will aid in making this adjustment Adjust Choke Fig 15 Hold choke valve closed and while holding the control rod up against the stop in choke thermostat bracket adjust upper choke control rod until it freely enters hole in choke shaft lever then lengthen rod two turns and connect CAUTION To minimize the possibility of deforming the control rod while adjusting always turn the vertical portion Do not crank the rod using offset portion Adjust Choke Unloader Fig 16 Check unloader adjustment by holding throttle valve in wide open position and insert a 312 wire gauge between choke valve lower edge and wall of bowl cover To adjust if necessary bend tang on throttle lever Final Adjustment 1 Install air cleaner assembly 2 Start engine and if necessary readjust carburetor idle speed and mixture 3 Shut engine off remove instruments then connect choke vacuum break hoses and install spare tire CORVAR SWOP MANUAL