Carb slide - vacuum piston modifications

[tnastvogel]

Hello. I recently bought a jet kit from this company 6sigma racing. Along with some jets and needle shims, they sent me a #59 (very very small) drill bit to drill out an additional vacuum hole in the carb slide. The theory makes sense - another small hole will change the vacuum effect and allow the slide to move up faster giving faster throttle response. Fine.

I really don't have a problem with the bike's throttle response. It's pretty quick around town, and of course it's only a 250. But would I mind if it had a little more pep off the line? Not really, no.

The only thing that bugs me is the disclaimer that accompanied the instructions for how to do it, which read something like, "This modification could have serious adverse effects on the drivability of your motorcycle". Also, most people on other forums that I've read say not to do it. But in none of these forums were they discussing GZ250's.

So I'm wondering if anybody has ever done this modification to a GZ250 and, if so, what were the effects?