If the o-rings are OK then its not coming from there.

If the intake pipe-carb connection is leaking then the orings are not sealing. Also you could have a leak from the black plastic check valve or the oil could be coming directly from the carb air opening.

There is Zero fuel air mix going up that intake pipe and only a small amount of oil possibly.

The real question is are you getting oil, or raw fuel? Raw fuel is not in the intake pipe, so the only place this could be coming from is the black plastic check valve on the injector line. If its spitting back oil from the bottom of the end of the engine this is likely coming out the carb intake, and spitting up onto the intake Pipe that goes to the head.

If you have too much oil being spit out then trying leaning the pump just a little and see if it stops it. Excess fuel and oil that is not being spent could spit out the carb inlet. This is a normal thing if its way on the rich side. Otherwise its coming from somewhere else.

Troy Newman
Team YS