I have an OS 91 Surpass II w/pump and I have a question. I'm adding the three lines to the fuel tank as suggested but I am wondering if the vent tube end is in the best location. I have the vent tube running out the front of the tank and pointing down and out the bottom of the plane. Would it be better exiting out the top or does it really matter? I have a feeling it really
doesn't matter but I thought I would ask.

It doesn't really matter. I have one out the bottom. It hasn't caused any trouble. There's another guy at the field that has his sticking forward. Didn't seem to matter.

Enjoy,

Jim

Ideally, the fuel tank vent should run from the top-center of the tank and flow out the bottom of the model. This way, fuel won't flow out of the tank when the model's in various attitudes. With the vent going from the top of the tank, it also is the overflow for fuel when you're fueling the tank.