Fei Bao MiG-21 Fishbed Instruction Manual (Draft Rev 0)
Page 10 of 24
The 2" length of brass tubing helps to prevent the clunk line from falling forward also reduces
the clunk’s ability to reach the bottom and top of the tank. A slight bend (approx 10 degrees) in
the brass tubing at the stopper as shown in the photo below will bias the line allowing the clunk
to reach the bottom of the tank.
The bend prevents the clunk from reaching the last 4 oz of fuel in each saddle tank when the
plane is inverted. This is not an issue since the saddle tanks feed the main tank. If the model is
rolled inverted when the saddle tanks are almost empty, fuel will be supplied from the main tank.
Once the model is returned upright, any fuel left in the saddle tanks will immediately be drawn
into the main tank.
Tip: Mark the exterior of the tank with an F (fuel) or V (vent) to help prevent connection errors
when installing the fuel lines to the tanks.
