I really need some opinions here. I swapped down to a 19mm from a 19.5mm, kept the same jetting but now at WOT with load i get a sputtering. Before anyone asks, the reason i swapped was that through all of the learning, jetting, screwing, and unscrewing, i stripped a couple of the screws that hold the float bowl on which lead to a nice little fuel/air leak. I haven't got to take it out for a good test run, just rode it around the yard for a few minutes.
So this brings me to the question, which i asked before but didn't get very many responses, is .5mm going to make a huge difference?