I was given an old Poulan Pro top handle saw several years ago, I think a model 25, and through my neglect, it no longer runs. To be honest the guy who gave it to me said all the good had been used out of it, but I have used it to cut a good volume of firewood and take down a few pines nearby. So, the saw will no longer start, I assume from leaving gas in it so long, but it never would idle, always had to keep goosing the throttle to keep it going. What is a good source of info to rebuild the carb and make the proper adjustments to it? Also are parts available for something as old as I think this is? Any replies appreciated, Clem.