ORIGINAL: xup1234
It looks like it is coming out where the exhaust meets the motor. Soon to find out that gasket is bad. But if the gasket was good it would seem like there was a lot of nitro going into the pipe, which cant be good? And where can you get the back plate, i have looked but cant find the one for the hyper .21
Thats because its very rich. Have you finished the break in procedure? If so lean it out more as it sounds like you way off a decent tune. As for the seal, have you moved the engine or pipe? perhaps its not sitting on the gasket properly?