New member here with no experience with 2 cycle engines and I have my great uncle's XL-12. I cleaned the carb and got it running, but it's a bear to start (floods pretty easy I.e. very wet spark plug) and won't stay running. After warm up, it will start easier and idle, then when I run it up to full throttle it runs for a short time and then dies. This is an old blue model SN 03430933 with thumb oiler. Carb is a Walbro SDC 29-1. Now I'm stuck trying to figure out how to keep it going and things I need to look for. I have a new fuel filter and fuel line to put on, but have not done it yet. Any suggestions on which gas to use? Other ideas that might cause this behavior? I has been sitting for over 20 yrs.