Stunting and being a squid are seperate but usually related phenomenom. Ignore the fun haters.. Wheelies are like masterbating: big smiles and fun to perfect your craft, but not a good idea(or publicly acceptable) in front of crowds or even single police..

Everyones doing it, and everyone thinks you'll go to hell for it, too..
Regardless, RCs can and do pull (unintentional of course)wheelies with out ill. I've heard Ducs tend to puke oil out the front air intakes during extended monos. The crank breather fouls and send oil up the hose to the airbox.
I found a disturbing amount of oil in my RCs airbox during filter changes. When I track prepped the RC I noticed oil mist coming out the breather hose and would accumulate a bit in the catch bottle.. I revised my breather hose routing, mounted the catch bottle in the tail, and modified the internal breather mechanism built into the front valve cover.. A little mist may reach the catch, but no noticible accumulation..
I think Thorsten's oversize breather outlet is a godd idea, as twins push a lot of air under the pistons..

??? Anyone tried a breather outlet on both valvecovers?? Any reason we don't/can't put the vent on the rear cylinder ?? My only guess would be more oilmist/air pumping issues.. Something like the old Gixxers pumping up and venting oil during high speed runs?