RCB 9C-327



	Rochester Carburetors 1958 CHEVROLET TRIPLE TWO BARREL CARBURETOR INSTALLATION ADJUSTMENTS AND SPECIFICATIONS				BULLETIN 9C-327 PAGE 3 OF 5 DATE: 1/15/58


FRONT AND REAR CARBURETORS
DIMENSION 1-5/16"			GAUGE BT-136

CENTER CARBURETOR				SETTING l/32"—(.031") With throttle valves completely closed there should be 1/32" clearance between the tang on the pump lever and actuating post on the vacuum switch. To adjust loosen the two retaining screws holding switch to bracket and move switch assembly up or down to obtain the desired clearance. CAUTION: Make sure actuating post on the vacuum switch is in the full up position before checking clearance. Tighten switch retaining screws after making adjustment.
DIMENSION 1-1/4"		GAUGE BT-129
With the air horn inverted and the gasket in place, position the float level gauge over the float so it rests against the pump side of the power piston shaft, with the outer leg in line with the center of the float. Bend the float arm as shown until the float just touches the bottom of the Gauge.

				SET MARK ON COVER TO SPECIFIED POINT ON CHOKE HOUSING AUTOMATIC CHOKE ADJUSTMENT (Center Carburetor Only)
				SETTING - INDEX Loosen the three retaining screws and rotate the coil cover counter-clockwise against the coil tension until the index mark on the cover is in line with the specified mark on the choke housing.
SETTING 1-29/32", GAUGE BT-129 OR SCALE The float drop is correct when the distance from the air horn gasket to the bottom-of the float is 1-29/32" with the air horn held upright. Bend the float tang to adjust; toward needle seat to lessen drop and away from needle seat to increase drop.



SETTING 15/16", GAUGE BT-136 Back off fast idle and idle stop screws and hold the throttle valves completely closed. Check the distance from the top of the air horn casting to the top of the pump rod as shown. Bend the pump rod with Bending Tool BT-18. Use gauge BT-109 to obtain the specified setting of 15/16".				SETTING .089", GAUGE BT-108 Place the fast idle screw on the second step of the fast idle cam next to the high step. Make sure choke trip lever is in contact with the choke counterweight lever. Bend counterweight tang as shown so that gauge just fits between the upper edge of the choke valve and air horn wall.

CO, WD, 131, 149, 9X, 9FR, 9FD				FORM NO. 1255 I.P.S. PRINTED IN U.S.A.