noob needs help with mileage - only 10 MPG!

You've probably got a problem with your carburetor. See here for what I've seen cause ridiculously bad mileage despite the engine running well. Carburetor operation and repair manuals and links to training movies and carb repair/modification threads are posted here for free download. Tune-up parts and technique suggestions in this thread. And don't forget to keep on top of the valve adjustment.