Fuel pulling out of vents!!

Ok I need help with this one. I gave my OS Max-S .30 a test run on my new plane over the weekend. When it's running the air from the prop as it goes over the vent tubes is pulling the fuel out of the tank! How can I fix this? Do I cut the vents at an angle?

Tim,

Assuming that they are straight vents and the air is traveling across them at a 90 degree angle. Yes, one solution is to angle the vents towards the incoming relative wind. Another solution is to remove one vent (top vent) and replace it with tubing that is bent towards the relative wind and use a piece of tubing on the bottom vent that is plugged so that air pressure cannot blow fuel out of that opening. Of course the best solution is to use a uniflow vented tank. It will already have tubes oriented in the proper direction. Leave the uniflow vent open and cover the overflow vent. This will give a more constant engine run while manuvering. It will also make th engine go slightly richer when flying into the wind.

Hope this helps

Or you can use tubing that turns both vents into the wind. You will see some richening in the air, so consider this when you needle the engine. It might take a flight or two to get it right.

The easiest way is to cut fuel line at an angle and slip it over the offending tubes with the angle facing into the wind.
Bare

LAST EDITED ON Jun-17-02 AT 01:39 PM (CST)

Here is a simple idea to try.

http://www.aeromaniacs.com/busholator.htm

Instead of cutting a notch in the fuel line, I filed a notch in a short brass or copper tubing and connect the two fuel lines at each end.

Eric Lee