[SpudRider]

The CSC Blog just announced the official word on the orientation of the oil contaminant separator (OCS). CSC says the clamp should be at the top, and the hose connected at the bottom, as shown in the link below.

http://californiascooterco.com/blog/?p=21183



CSC is employing the exact same logic we concluded on this forum, but is aiming for a different result. Placing the OCS in the CSC orientation maximizes the amount of fuel collected in the clear tube at the bottom of the OCS. Placing the OCS in the opposite orientation minimizes the amount of fuel collected in the OCS, and sends more atomized fuel to the air box, where it can be burned in the combustion process.

Less than a week ago I received a personal message regarding the OCS orientation from forum member Fritz, in Bavaria, Germany. I hope he doesn't mind if I post part of his message.

I found something related to the fuel in the overflow line. According to the drawing in the documents showing the recirculation system, the orientation of the OCS is actually mounted correctly from the factory assuming the US setup is the same as the European.

Considering the fact that mounting it upside down will reduce the amount of fuel in the line I have an idea why it is still mounted as shown on the drawing.

A gas recycling device is probably compulsory so they added it. But burning this recirculated fuel can actually influence your emissions in a negative way. This is due to the fact that the fuel from crank case can not be considered by the ECU with this system setup (additional valve and carbon canister including a load model would change that) and therefore enriching the mixture in an uncontrolled manner. Which means only the feedback control of the lambda sonde can compensate when it is actually already to late and the lambda value is no longer 1 and the catalyst is not working at its most efficient operation point.

On the other hand I guess there is no regulation limiting the amount of fuel collected in the line since it is assumed that it will be disposed correctly.

Long story short the mount of the factory is correct according to the drawings provided for European type approval including emission testing.

So there you have it. Mounting the OCS as shown in the photograph above is the offical orientation. As we have proven, it will result in more fuel being collected in the clear tube, and less fuel being added to the combustion process. This orientation is probably stipulated by exhaust emissions criteria, more than anything else.