Chainsaws

I purchased a Poulon Pro Chainsaw April 2013. It worked fine up until yesterday. I can start it OK, but the engine dies as soon as I apply any power. Will adjusting the carburetor settings help? If so:
1) Where can I get a tool to adjust carburetor?
2) How to adjust the 'H' and 'L' labeled screws. Turn clockwise, counterclockwise? Turn both same direction? How much?
Thanks!