If ANY model engine will run "all day" on the test stand, but not in the airplane, it's not the engine's fault. Something in the engine, airframe, and fuel system combination.

Usually, when an engine quits shortly into a run, it's going too lean for some reason. Airframe vibration is a common cause that agitages air into the fuel and causes a lean mixture. Sometimes, it's a plugged vent line. As fuel is drawn from the tank, air cannot replace it, so a partial vacuum builds in the tank and opposes fuel flow to the engine, which quits from fuel starvation. Of course, leaky fuel lines, cracks in the metal tubing in the tank, and so on are also causes, and everything needs to be checked.

The spraybar in the carb can easily be clogged by all sorts of trash. Remove it from the carburetor and run a fine wire through it to push out anything that may be there.

Please see the SuperTigre Direct Support Forum for how to set the carb. We've posted that in a "sticky" thread at the top of the forum. Setting the carb as we describe is essential. Also, don't try to get a too-low idle RPM. If you do that, you'll have problems with transition and midrange.