Bike won't rev unless covering intake

[Millertyl]

I' having headaches here. Ive been working on my bike for the last two weeks and haven't gotten to go riding yet. The bike will start and idle, but won't rev and makes no power. I was testing the electrical system today and a gentleman walked over and talked to me for a bit. He knew motors and put his hand over the intake on the air box and the idle jumped up and I was able to rev the bike to red line. It was great hearing that noise, but now I need to trouble shoot. I just cleaned the carbs yesterday. The bike sat for 2 years and needs some attention. 3 of the 4 slides were stuck but I pulled all of them and cleaned them and the needles. I pulled all the jets and soaked them in cleaner and cleared them, put in new gaskets and set the float heights with the dry method. I inspected the intake boots, which were replaced the year before I put it away for two years, and they all seem perfect yet. Im pulling the carbs apart now again. What should I look for? Im so confused. Please help so I can get her back on the road