Carb fitment to manifold O ring

[graggy]

Here are some pictures of my carb. It looks like the only thing that keeps from getting an air leak to the manifold is a o ring. Is this normal and do you really have to push it on hard while tightening it up so it doesn’t leak air?

 

[Whitewill1412]

That's a bofeng carb and yes and yes

 

[GW's Motorized]

Depending on your engine you can use the c&c cdh power intake that has an O ring built into the side. I recently installed this on my bike and it seems to run great, I however haven't ridden it yet