Won't go over 3000 RPM, Cuts out high speed, fuel starved, fixed!

When I first bought the bike and did the carbs, I put it all back and had this problem, found out the fuel line to petcock was 3/4" too long and kinked. Ran great for 500 miles then had a fuel leak. I replaced the bad o-rings on fuel rail and then had same rpm problem happen again. Tried EVERYTHING to fix it. finally found the answer buried deep in these posts. Thought I would repost my problem to help the next guy. So the vent line coming from the carbs, I didn't know where it goes. there is extra holes in the airbox so I just connected there, thinking I was saving the world from pollution etc.. Turns out it caused a vacuum somewhere causing cut out at high RPMs. Hope someone facing the same problem will read this. BTW I used the cheap $20 kit off ebay. Will let yall know if the needle float valves hold up. drove 250 miles yesterday with no problems.