From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Service bulletin for a Stromberg carburetor detailing acceleration and fuel level systems with diagrams.
| Identifier | ExFiles\Box 122\2\ scan0254 | |
| Date | 1st November 1936 | |
| STROMBERG CARBURETOR SERVICE BULLETIN AUTHORIZED STROMBERG CARBURETORS SALES & SERVICE ACCELERATION For accelerating requirements it is necessary to supply momentarily an extra amount of fuel when the throttle is opened. On the up stroke of pump piston (33) fuel is drawn into the piston chamber through the inlet check valve (37). On the down stroke the compression closes the check valve and forces open pump by-pass valve (36). The fuel is then discharged through pump discharge nozzle (39) into each of the carburetor barrels. When the throttle is opened part way only a small amount of fuel is discharged. Two holes are provided in the throttle lever for accelerator pump rod. The hole on the short radius gives less pump discharge and should be used in warm weather. The hole on the long radius gives more pump discharge and should be used in cold weather. FUEL LEVEL Fuel level in the float chamber is maintained by floats (17). The level is set at the factory at 5/8" below the top surface of the float chamber which corresponds to the bottom of level sight plug (43) with the engine idling. The plug should be removed to observe the position of the level before the carburetor is dis-assembled to re-set the float. When resetting the floats it is necessary to remove the air horn assembly. Holding the air horn in an inverted position, Service Tool SER-292 should be placed on the cover gasket. The top of the vertical guides of the tool should be flush with the tops of the floats when floats are properly set. The guides also serve to check the clearance between the floats. The floats should be set so that they are tangent to the guides without drag. This will allow sufficient clearance with the main body and not interfere with free movement. If the float tool is not available the distance between the top of the float and the gasket should be 1-13/32". IMPORTANT: Fuel level can be checked only when engine is running. DO NOT START ENGINE WHILE AIR HORN IS REMOVED BECAUSE A BACKFIRE THROUGH THE MANIFOLD MAY CAUSE A SERIOUS FIRE. PARTS LIST 17. Float 18. Float Lever 19. Float Needle Valve Clip 20. Float Fulcrum Pin 21. Float Needle Valve 22. Float Needle Valve Seat 23. Float Hanger Gaskets 24. Float Hanger 25. Float Chamber Vent 26. Pump Fulcrum Arm 27. Pump Piston Link 28. Felt Dust Washer 29. Retainer Washer 30. Dust Washer Spring 31. Spring Retainer Washer 32. Pump Duration Spring 33. Pump Piston 34. Piston Expansion Spring 35. Pump Relief Valve 36. Pump By-Pass Jet 37. Pump Inlet Check Valve 38. Pump Discharge Channel 39. Pump Discharge Nozzle 40. Spark Control Hole 41. Fast Idle Rod 42. Pump Rod 43. Fuel Level Sight Plug 44. Throttle Stop Screw 45. Fast Idle Cam BENDIX PRODUCTS CORPORATION STROMBERG CARBURETOR DIVISION (Service Stations All Over the World) 401 BENDIX DRIVE SOUTH BEND, INDIANA Printed in United States of America | ||