On the intake boot- I've never had an issue with that spring type thing at all. If I were to and wanted something different, I'd buy the intake clamps (like pipe clamps) from a bigger Husqy/Jons/Stihl) and use that. BUT, it seems to me you have other issues. First, check your fuel line / filter. If the fuel line has a stress crack that gets pulled open when the saw is turned it could open up, suck air and cause the issue...then close when sat upright. Also, make sure the fuel filter is loose and free and not hung up in the tank somewhere- same thing, it is submerged when upright but comes out of the fuel on its side, pulling air and raising RPMs like some saws do as they run out of gas. Next idea, do go ahead and clean your carb as mentioned. Something might be blocking the jet either restricting flow or making it so that you don't get proper atomization of the mix, so too liquid fuel can pool in the venturi and affect running. This is more an issue on earlier barrel valve carb types on weed eaters, but what the hell, may as well think about it!