I'm having the stalling probs with my 2.5 as well, though not nearly as bad as it was. I believe it has something to do with vapor lock. Have any of you tried the longer piece of fuel line (pressure line) from the exhaust to the fuel tank? I installed a piece approx. 17-20 inches long, enough to make 2 loops (I just wrapped mine around the rear body mount on my Maxx. This helps the stalling problem. Mine still stalls ocassionally, but not nearly as much as it used to. Installing a Nova Pro head will help it run cooler as well. It's supposed to run up to 40% cooler with this head. Mine seems to run cooler with it.