Premature revving problem
I'm working on a 2001 Yamaha V Star 1100 Classic. Last year I installed a Hypercharger and full Cobra exhaust system. I've tuned the carbs to closely match my intake and exhaust configuration, however, I'm having a persistent issue with the bike. I don't remember if the problem existed prior to the mods. With the bike running, in neutral, and I give it just a little bit of throttle it revs up quite a bit. It's not a gradual increase. Today I thought it might be a good idea to check and make sure the carbs were in sync, which they are. But, I noticed that when it revs up, the front cylinder starts pulling way more vacuum than the rear cylinder. If I hold the throttle steady, eventually the vacuum will even out between the front and rear.
I also found no vacuum leaks. Diaphragms are seated and are in good condition.
Help please & thank you!!