Note: Picture to be used for reference only. Carburetor models may vary.

Note: Please read all the WARNINGS below. 


a) Use the small screwdriver or pliers to unhook the spring (33) from the accelerator pump lever (34). Disconnect the accelerator pump rod (1) from the ball sockets at each end. Disconnect the choke valve tension spring (14) using the pliers, and remove the choke lever fulcrum screw (1). Remove the five airhorn screws (31) and their lock washers. Lift the airhorn (32) off, with the accelerator pump attached

b) Remove the small cotter (split) pin from the top of the accelerator pump (10), then remove the screw (35) to release the accelerator pump lever (34) from the airhorn. Now you can remove the accelerator pump down through the casting.

c) To disassemble the accelerator pump, remove the felt seal (22), steel washer and top spring off the top of the pump first. Now pull the big lower spring downwards, pulling the retainer cup washer with it which allows you to pull the spring cup off the small groove in the rod. Slide the big spring and washer up the rod and off the old pump. Assemble these parts onto your new pump – big spring, cup washer, cup, small spring, steel washer then felt, from bottom to top. If any of these parts are past their best, think about a new full pump kit. Ask your Genuine Stromberg dealer for 9630K.

d) Now install the assembled accelerator pump back into the casting, taking care not to wrinkle the leather seal or catch it on the slot in the pump well. Place a new airhorn gasket (20) in the correct position on the bowl casting, and slide the airhorn back on, inserting the top of the accelerator pump through the correct hole in the airhorn as you do so. The felt washer goes on the inside of the airhorn. Now fasten the airhorn down with the five lock washers and screws to 5in/lb torque. Install the other parts removed above in (a) in reverse order, keeping the pump low in the carburetor. Attach the accelerator pump rod (3) before hooking up the fulcrum lever spring (33) to avoid catching the leather pump seal.

You’re done! If you think we’ve missed anything or we could improve on this Genuine Stromberg ‘How To’, please let us know. Email us –