Only runs without snorkel

04 Aerox with stage 6 streetrace 70 kit, Stage 6 sport pro ehaust, 17.5 Dellorto and standard airbox with mallosi filter. Whatever I do I cannot get the bike to run properly with the snorkel in place. With it removed the bikes a flier, but with it in place it seems like it just can't get enough air and it bogs down.

If I run it without the snorkel what size main jet should I use?

I'm concerned because I don't want to run with the mixture too lean

 

surely if its runs mint without it thate means the jetting is bang on i would say