ROCHESTER CARBURETORS

Bulletin 9C-330 15 December 1957

	BULLETIN 9C-330 PAGE 4 OF 4
		SETTING .015" - TOOL BT-91A With the choke valve partially closed, there should be a clearance of .015" between the lockout lever and the fast idle cam, to allow free movement of the cam when the secondary throttle valves are closed. To adjust, bend with Tool BT-18 or Tool BT-91A.
	SETTING .043", GAUGE BT-131 With the idle screw resting on the second step of the fast idle cam and against the shoulder of the high step, bend the choke rod with Bending Tool BT-18 to obtain sufficient clear­ance to allow the insertion of the correct gauge between the upper edge of the choke valve and the dividing wall of the air horn.
		SETTING .015" - TOOL BT-91A With the choke valve fully open and the secondary throttle valves partly open, there should be sufficient clearance between the lockout lever and the fast idle cam to allow free movement of the secondary valve shaft. Adjust with Bending Tool BT-91A to the specification listed below.
			SETTING .235", GAUGE BT-131 Bend the unloader tang with Bending Tool BT-69 as necessary to allow the insertion of the proper gauge between the upper edge of the choke valve and the dividing wall of the air horn, with the throttle valves wide open.
	QUICK REFERENCE SPECIFICATIONS
	Carburetor No. 1957 Early—7009846 1957 Late—7012126 1958 1957-1958 Tune-up Specifications 7012128—P.G. 701 1108 Turbo-Glide PRIM. SECONDARY PRIM. SECONDARY PRIM. SECONDARY SPARK PLUG GAP—.035" BREAKER POINT GAP—.016" CAM DWELL—28° - 32° IGNITION TIMING — 4 BTDC AT IDLE IDLE R.P.M, POWERGLIDE—425 IN DRIVE SYNCHROMESH—475 NEUTRAL GAUGE No. BORE 1-5/16" 1-5/16" 1-5/16" 1-5/16" 1-7/16" 1-7/16" SMALL VENTURI 1/4" 1/4" 1/4" 1/4" 1/4" 1/4" LARGE VENTURI 1" 1-1/16" 1" 1-1/16" 1-1/8" 1-1/4" MAIN METERING JETS .048 .051 .048 .052 .058 .065 IDLE NEEDLE HOLES .046 — .046 — .046 — SEC. LOWER .038 — .030 — .035 — DISCHARGE MIDDLE .027 — .027 — .026 — HOLES UPPER .028 — .028 — .026 — SPARK DRILLINGS (4) .052 — (4) .052 (4) .052 — PUMP JETS (4) .026 — (4) .026 — (4) .026 — POWER RESTRICTIONS .037 — .038 — .057 — CHOKE CHANNEL .098 — .098 — .089 — RESTRICTIONS BY-PASS — — — — — — IDLE TUBE RESTRICTIONS .027 — .027 .033 — LOWER IDLE BLEED .033 — .033 — .048 — Adjustments DIMENSION DIMENSION DIMENSION 1957 1958 PRIM. SEC. FLOAT LEVEL 1-5/8" 1-11/16" 1-5/8" 1-11/16" BT-89 BT-89 BT-143 FLOAT DROP 2-1/4" 2-1/4" 2-1/4" 2-1/4" BT-93 or Scale BT-93 or Scale PUMP ROD 1-1/16" 1-1/16" — 1-1/16" — BT-195 or Scale BT-145 or Scale IDLE VENT — 31/32" 31/32" — — BT-145 or Scale AUTOMATIC CHOKE 1 NOTCH LEAN 1 N. L. — INDEX — — __ CHOKE ROD .043 .043 .043 — BT-131 BT-131 UNLOADER .235 .235 — .235 __ BT-131 BT-131 SECONDARY LOCKOUT .015 .015 — .015 — Feeler Gauge Feeler Gauge SECONDARY CONTOUR .015 .015 — 315 — Feeler Gauge Feeler Gauge
	FORM NO. 1258 I.P.S. PRINTED IN U.S.A.	SPECIAL TOOLS SHOWN IN THESE PICTURES ARE AVAILABLE THROUGH UNITED MOTORS SERVICE DISTRIBUTORS

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