I'm running a MA 13x8 3 blade prop, i solder on a brass pipe on the regulator cover and routed it to the inside of the fuse, it did the same thing today but when i went to unfuel the plane it would not come out so i think i better pull the tank out and see what's going on. Now i think the vent line was plugged on the tank on the test bench but it is open now, should this line be plugged? Also i haven't put a muffler on yet, would the lack of backpressure be part of the problem ?