PJ and I worked on drilling slides together to no good result. Dont drill the slides.
I dont know if he continued w the work alone, after I gave up.
its possible his post just may be "theoretical" thinking out loud.
You can continue working w the JBMs. But sorry to say my JBMs went straight into the trash. My bike wouldnt even try to run with them. Anything past 2500rpm was shit. I ended up w the new Honda slides, daphragms and springs, kit #7 from phish, I believe. And it really paid off w a huge improvement. Im not gonna tell you it was a total "plug and play" type situation as my carbs are HEAVILY modified. the Honda slides may or may not help you as much as they did me.
Glad I could help finding the torn diaphragm...Sucks you found a torn diaphragm.