lefty wrote:Would you suggest some loctite on the screw?
Yes, either that , or if you can fit a punch through the throat and venturi, and a flat punch on the other side of the screw, lightly stake the end of the screw (peen it- a slight mushroom will prevent it from coming out and destroying the saw when it does) Loctite is far easier and safer if you have not had any experience/practice at peening throttle screws (it is wayyy to easy to put a bend in the throttle shaft that makes things go wonky!) But, don't remove the screw to apply loctite if you can let the thing set untouched for a few days (let a tiny drop of loctite harden on the very tip of the screw - once cured, it becomes sort of a plastic bonded to metal, which again keeps screw from coming out) However, if you need/want to have the thing in service right away (most cases) then yeah, pop screw out (not needed to remove it completely if you can get a drop of loctite on threads before removing it.)
Often, OEM factory screws especially in potential high vibration applications, will have the ends of the screws staked or peened at the factory- (which if not aware of it, can often cause an unwary tech with a screwdriver to have to replace a throttle shaft too! - Peened screws will ruin soft brass threads in throttle shafts) - on those, the tip of the screw has to be filed or ground away flush to the throttle shaft before trying to remove it, and plan on replacing the screw for re-assembly.