Have this engine mounted in a 40 size U-CAN-DO using the stock fuel tank. When I first built this plane the engine ran great for about 10 flights before acting up. Before sending in I tried running it but could'nt get it to fire, tried adjusting the regulator both in & out with no difference. Have not tried running it since getting it back repaired since it's acting the same as before. I'll try readjusting the regulator sometime this week turning it in(lean) & hope for the best.