RE: Fuel tube size for 95AX and 1.20AX
For up to a 1.20-size engine, we just use regular medium tubing. If an engine will run for only a few minutes while flying and then quit, it's going lean. Usually, this is because there's not enough fuel pressure. Your muffler may not be able to pressurize the fuel tank enough to give you good fuel flow. This is quite common with aftermarket exhaust systems. You may also need to check the pressure lines to make sure the tank is actually being pressurized. Running a too-large prop will also cause problems. Make sure the engine is getting well cooled. O.S. recommends using large props for low noise. Lower nitro content will also help because the engine will run cooler.