Documenting how i fixed my homelite gas trimmer. Bought it at a garage sale for $10 plus new gaskets $5 and it took less than 1 hr to get back up running.
I bought the gaskets on eBay. Amazon had some, but they were a little more expensive: http://goo.gl/JGNLju
You can buy carb cleaner at any auto part store or hardware store.
Finally, if you want to replace the welch plug:    • Briggs & Stratton 6.5HP lawn mower ca...