Hello experts.....

Coudl someone explain to me in detail what the little channel between the carb intake and the frontside bearing is for besides lubricating it?
I "heart" a story which says something about pressure balance etc...
Reason i'm asking is I want to know the truth about whether a crankcase cap on the front is actually helping keeping out unwanted air through the frontside bearing making the tune more easy or at least widen the tune bandwidth a bit.
The only thing i can imagine is that when the crank is passing bdc the piston starts sucking in the mixture and to prevent unwanted air through the bearing due to the lower pressure at that particular moment it sucks a tiny bit through this channel making sure no dirt is sucking in.

I don't know whether this al makes sense or not as Im a newbie at nitro engines learning every day...

cheers

w.