The oversized shaft myth
Many rebuilders feel the need to replace the throttle shaft in a Stomberg 97 with something larger, due to the wear and tear on the bushings. There is no need for this if you follow the advice of the Stromberg techies.
The shaft sits in two bushings – one on each end of the base casting. The Throttle shaft and Lever kit - #9581K comes with
two new bushings.
Take the base off the carb, then remove the throttle plate screws and pull out the plates – noting which way they go as they have an angle on the edge. They are marked with a crescent mark. Pull out the shaft and you will see the wear where it hits the bushings.
You may need to heat up the base to remove the bushings. Grip them with a plumbers wrench and twist them out or drill them carefully. Replace with the new
bushings. They will be a very tight fit so align them carefully and remember to capture the choke kicker behind the larger bushing. When they are pressed in, they will need line reaming because they close up in installation and need to be aligned to each other. You will need to purchase a 0.278" reamer and run it through both ends. Then reassemble.
This process will eliminate any air leaks and the need for a larger shaft.