RCB 9D-7 Model "BB"

Bulletin 9D-7 August, 1951 Model "BB" Page 11 ROCHESTER PRODUCTS, DIVISION OF GENERAL MOTORS, ROCHESTER, NEW YORK 7. If wear is noted on steps of fast idle cam, it should be replaced as it may upset engine idle speed during the choking period. 8. Inspect pump plunger leather. Replace plunger if leather is damaged. 9. If gaskets appear hard or brittle, replace to insure a proper seal. 10. Check to see that lower end of choke suction tube is tight in seal in throttle body. If not, a new seal will have to be installed after the carburetor has been completely assembled. 11. Inspect suction tube nut packing. If compressed or out of round, replace. ASSEMBLY AND ADJUSTMENT IMPORTANT; To prevent poor economy due to fuel leakage all threaded parts must be installed tightly. This applies especially to the strainer nut and float needle seat. THROTTLE BODY ASSEMBLY 1. Install idle screw in throttle lever. 2. Screw Idle adjusting needles and springs into throttle body until they are finger tight. Back out screw 1-1/2 turns as a temporary idle adjustment. Make final adjustment on engine. 3. Install fast idle cam and fast idle screw to throttle lever. 4. Upend bowl, place throttle body gasket in position and attach throttle body. Tighten screws evenly and securely. NOTE: New choke suction tube seal, if needed, will be installed after carburetor is completely assembled. (See Page 15.)

BOWL ASSEMBLY With bowl again in upright position, drop small aluminum pump inlet ball into pump well hole and replace pump return spring. Install large steel ball in pump discharge cavity. Place spring and pump discharge guide on top of ball. (Figure 9) Press pump screen carefully into position. AIR HORN ASSEMBLY With Air Horn upended on a flat surface, install float needle seat and gasket, using screwdriver with a 1/2" bit. Place small pump vent disc and retaining clip into pump vent. Place Power Piston spring and Power Piston into vacuum cavity. Piston should vide free in cavity.	Pump Outlet Ball Pump Discharge Guide
	Figure 9