Carbking Jon,
2 things I noticed when rebuilding my carb:
Someone removed the spring from under the mixture screw an replaced the mixture screw with one from a 28 model carb
The second thing is that the carb drawing g shows a main nozzle under the main jet in the angled passage way under the bowl, mine did not have that nozzle piece.
Does the 228 use the nozzle or is that only in the 28?