can anyone advize?

[gusmanxtr]

My dirt bike has one of those air cooled cb250 engines in it. The inlet manifold has a capped of piece on it that looks like a tube can be connected to it. The head has a hole drilled through it into the exhaust port which is also capped. Does anyone know if these can be connected like an inlet air supply, boost kind of thing or if there is any benefit from doing so?
Gus.

[NZBrakelathes]

EGR probably and if you connect it you get cleaner emissions and less Hp!