I currently have what I think is a 16mm carb (19mm opening at intake) that needs to be replaced. Can I use a larger carb without modifying the engine. I'm asking because everything I'm finding that will bolt on is either listed as 19mm or 22mm. If I go with a bigger carb do I have to modify anything.

Is it possible that people are listing these carbs based on the intake opening size?

 

the carburetor size is measured at the exit opening where it bolts up to the intake maniford, here it should measure .748 inch or 19mm. so if you measured 19mm across the intake opening then you need to remeasure at the exit where the carb bolts up to the intake maniford. you shouldn't have a problem going up to a 24mm carb as long as you take the time and have the knowledge to jet it correctly,