Accelerator Pump Circuit (Rochester AA)
Throttle Shaft Leaking (Rochester AA)
This carburetor was developed by the Rochester Products Division, Rochester, New York was an entirely new design and differed from previous carburetors, as the air entrance is horizontal. The carburetor incorporated a number of distinctly new features of importance to the car owner and also the service mechanic. It was used on 1949 and 1950 Oldsmobile Rocket 88 and 98s.
Foremost of the major advantages of the new carburetor is the comparative low gasoline bowl temperatures during all driving conditions. This marks a definite stride forward in reducing vapor lock, and the minimizing of hot starting complaints. The gasoline temperatures in the carburetor are better than 25 degrees cooler than a conventional carburetor under all comparable conditions of engine operation. This feature is primarily due to the fact that the float bowl, containing the fuel, is suspended from the cover within the outer housing of the carburetor and cooled by incoming air.
The carburetor presents a new ease of service to the service mechanic. By the simple removal of the eight outside cover screws and the disconnection of the fuel line, the cover and bowl assembly may be removed from the outer housing for cleaning or inspection. Only in rare instances will the air cleaner and entire carburetor be removed from the engine. The cover and bowl assembly, which is the very heart of the carburetor, contains all the calibrated parts of the carburetor. This unit may also be purchased as a service assembly, thereby eliminating the need for a complete replacement carburetor.
Of importance also is the need for only four simple but important external adjustments. These are the choke rod, unloader, fast idle, and accelerating pump discharge adjustments.
Since carburetion is dependent upon both compression and ignition, the carburetor should always be adjusted last in engine tune-up. The fuel systems within the carburetor are basically simple and can be readily traced and understood.