ZX7R Air Box / Emission Question

I am wanting to return my Airbx setup back to normal to try and get the idle running well. I have had the bike in at one of the bike shops but they couldn't work out what was wrong with it. Feels like it's running on three cylinders but everything checks out fine. Bottom end is crap.
I am putting all the vacuum hoses back on and going by the manual, I cannot work out where one of the lines goes.

When looking at the 'clean air item', the front left hose goes straight up to the front of the airbox. The right hand hose goes down to a junction that seperates into two and goes to the carbs. The 'small' right hand side vac hose goes down to the inlet manifolds and the manual looks like it is connected to all four but from memory, mine was only connected to one. Should these be connected to all four to equalise the presures or is one good enough ?

I can't see in the manual what happens to the rear left hose. Any ideas where this one goes ? I dont have the vacuum piece in the middle of the two outlets which come out of the valve cover either. This was sealed when I got the bike but was running perfectly well without it.

Should the rear left outlet be sealed ?

Any help or pics would be greatly appreciated.

Only Carbies 1 & 4 are connected via vacuum tubing one to the air box the other to the vacuum type fuel tap....... Carbs 2 & 3 link together using some of the vacuum tube

Same as you would after balancing the carbs .
Balance 1 &2 > balance 3 & 4 > balance 2 & 3.........Kawasaki normally just fit plugs into the Vac take-offs in 2 & 3 (cheapskates.......I always forgot to remove the adaptors when selling the bike and have had to buy new every bike I owned)