motor shuts down while trimming up

[Moffett-cr.]

I just picked up a 05 tracker with 40 h.p. four stroke. Took it out got up on plane and started trimming up and motor shut down to an idle? tried it twice more and same thing. Thinking to much rpm? Looks to be a new prop (maybe wrong size)? Has anyone had this problem? Would anybody no the correct prop for this engine? Not looking for speed as much as economy.