Bens 160 fx is in a Giant Ucan do -side mounted with a Bisson pitts muffler and 1 exhaust plugged off
we reproduced the problem in my shop -simply by running it after we had pulled all the lines -cleaning the remote needle- checking for holes -airleaks , pulled the tank apart, etc . we started the motor held the fuse then started to slowly tip it slightly up, all was good till about 45 degrees and it suddenly stopped just like inflight conditions. This motor runs excellent on the ground and in level flight. good transition, nice power at top end, reliable idle, 18/6 zinger, he is running 15% fuel 18% oil Byron I believe, A warm Glo plug
Ben experiances this problem on split S entry or attempting stall turns with a dead motor each time.
the tank location is in the stock location We find no foaming or air bubbles
It is a head scratcher for sure. Seems like everybody who uses a pump just takes them off later so that really isnt a cure. There are literaly hundreds of these out there with the same setup, and i have not heard of a problem like this, We are at about 1000 ft altitude at our field

The carb does not seem to be loose in the barrel but there seems to be weak fuel draw on the upline I have wrinkled my thinking cap on this one. anybody else got any input as to cause ?
Don Olsen
Evening Air Hobbies