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So I took a look at the system a few minutes ago and really not quite sure just why they went that route. Airbox sucks off the high point of top tube. Crankcase inputs just below. Rocker covers breathe off near the low point of the pipe.There's a big line from a high crankcase vent with an "exhaust only" check valve in the circuit.There are two small lines coming from the rocker covers to the frame cross brace tube. These connect to the crankcase through the oil drain holes in the heads cylinders and crankcase. Those lines should vary with crankcase pressure as there are no valves in the line.Finally there is a small line high on the top tube that connects into the air box. It should be under suction at all times when the engine is running.In a perfect world the crankcase would be at a varying negative pressure as the one way valve dumped whenever internal pressure hit atmospheric. But ring blow by and the venting through the rocker covers will all effect that. As will the vacuum from the air box.Now my /2 BMW and Ural both have a timed disk that opens the crankcase to the atmosphere once each crank revolution. This vents to the atmosphere. Essentially they let the pistons bounce back & forth on crankcase pressure, but dump the pressure once each crank revolution. I assume this is to dump whatever gasses blow by the rings and start anew at atmospheric pressure bext cycle.Now if I remember correctly the BMW R100 just has a one way valve and vented into the intake with a small drain hole enroute to dump condensed oil vapor back to the sump. So that would keep the crankcase at atmosphere or below (minus blowby) because of the one way valve.So it would almost seem that I could plug a rocker cover vent and the airbox line. Then I could put a vapor trap in the line from the crankcase and drain the vapor trap into the remaining rocker cover line. Finally the crankcase line would vent to the atmosphere to dump extra pressure created by ring blow by. Or maybe just ignore the whole thing. I'm not an engineer. But I'd want my vapor trap being cooked by engine heat to eliminate moisture.Frankly I don't understand why this mayo is an issue on my bike as it does get heated up. It is my choice for long rides. OTOH it did come with an oil temp gage and I never saw that go much above 100° C no matter how or when it was ridden.