Can anyone direct me to information regarding the modification of Walbro carbs? Specifically, what can you do to enlarge the venturi and what is the technique to do this without destroying the carb?

On a related note, given the huge range of Walbro carbs how much do they actually differ between similar styled/sized models? Would hogging out the venturi require other parts to be changed?

Yes, this is related to the WT275 I mentioned previously. Just wondering what can be done to enlarge it from 7.94mm to around 11mm and whether such a mod would exceed the jetting limits and such like?