Sounds like it is too lean, i.e quitting on climb after a couple minutes, screaming power while cruising, etc. Try richening it 1 or 2 clicks, it may be a touch rich at first but it will lean out as you progress through the flight and as the prop unloads in the air. In other words, tune a few hundred rpm down on the rich side after a quick warm up. Might need to richen the low speed a touch also.