Mazda rx7 nikki
 

Got a nikki carb for my rx7 series 3 but has some differences.
The new one has the air vent solenoid section blocked off with a welch plug from factory and no place for the vacuum hose.
Does anyone know if there is any effect on how the car performs without the solenoid and why it was designed without one?
Where do the vapours go in the new one?
I have attached photos of both my original one and the new one going into it.
https://cimg8.ibsrv.net/gimg/www.rx7...7360d7287a.jpg
https://cimg0.ibsrv.net/gimg/www.rx7...6f07bdea6d.jpg