|1968-69 Rochester H & HV Carburetor Adjustments|
Back out the idle speed screw until the throttle valve is completely closed, then bend pump rod as necessary to align index mark on upper pump lever with sharp edge of air horn casting.
|Idle Vent Valve |
Close throttle valve to the point where vent valve just begins to open. At this point, measure throttle valve opening by inserting gauge of correct size between valve and bore directly opposite idle mixture screw. If throttle opening not correct, bend tang on throttle lever as required. Be careful not to bend vent valve spring arm.
|Vacuum Break Diaphragm|
Press diaphragm plunger inward until seated, close choke valve to point where connecting link is at end of slot in choke lever. Check choke valve opening by inserting gauge of correct size between lower edge of valve and air horn wall. Adjust by bending connecting link at the angle as shown.
With air horn inverted so that weight of float is holding needle valve closed, and with gasket in place, measure from gasket surface to bottom of each float. Adjust by bending the float lever tang, which contacts inlet needle. Bottom of floats should be parallel with air horn surface. Floats should also be aligned to prevent interference with the sides of the float bowl when installed.
Float level: 1 1/16"
With the air horn upright so that floats hang freely, measure from the gasket surface to the bottom of float at toe or free end. Set by bending the tang at rear of float arm.
Float drop: 1 9/16"
Position fast idle tang on second step of fast idle cam and against shoulder of highest step, close the valve so that trip lever on choke shaft just contacts choke tang on lever and collar assembly. Check choke valve opening by inserting gauge of correct size between lower edge of valve and air horn wall. Adjust by bending tang on trip lever up or down as required. Setting: .190"
Hold throttle valve wide open and move choke valve toward closed position until contact made at unloader tang. Check choke valve opening by inserting gauge of correct size between lower edge of valve and air horn wall. Adjust by bending unloader tang on throttle lever. Setting: .510"
This adjustment must be made with carburetors installed on engine. With choke valve completely closed, pull choke rod upward to end of travel. Bottom of rod should be even with top of hole in choke lever. Adjust by turning rod in or out as required. Careful - Rotate vertical section of rod, do not crank rod by turning offset portion.
|Secondary Carburetor Lockout - Model H|
Three separate adjustments required. Adjustment 3, must be made after all carburetors installed on engine.
1. With throttle valve closed and edge of throttle lever lockout tang flush with lockout lever, bend throttle lever tang as required to get a clearance of .020 between throttle lever tang and notch in lockout lever.
2. With throttle lever in locked out position, bend stop tang on lockout lever as required for clearance of .060 between stop tang and bottom surface of air horn.
3. This is a linkage adjustment and must be made with carburetors installed on engine and linkage connected. After linkage adjusted so that all carburetors operate simultaneously, insert a .250" gauge between base of vacuum diaphragm and choke shaft actuating lever of primary carburetor, open choke valve until actuating lever contacts gauge. Bend tang on secondary carburetor so that it contacts choke shaft and fully opens choke valve. In this position, lockout lever should clear throttle lever tang.