Engine run problems

Gents: Here is the situation. The plane is a profile Ringmaster, the engine is a Fox .35. gas tank is a 3 1/2 oz. un baffeled non uniflow tank. Now here is the problem. When going into a inside loop the engine stops. ARGH!!!!. Please what am I missing. Because it didn't do it last year. Thanks Steve D.

If it quits when the nose goes up my guess is either the needle is set too lean or you have a leak in the fuel line somewhere.
Nils