Sounds like a wing warp, as Tom says, causing one wing to stall before the other. If you don't have an incidence gauge, stick pins in the centre of the leading edge and trailing edge, at the root of both wings. Do the same at both tips. Prop up the tail till the root fore and aft pins measure the same height from the table. Now do the same measurement at the tips. The fore and aft pins at the tips should be the same height from the table. A little washout wouldn't hurt, but wash in is a no no. Hopo this helps. Can be done without the fuse. if you prop the wing up level on the table.