It takes three steps to truly clean the entire fuel system. The first step is to clean the air-intake and throttle body. The second step is to thoroughly clean the combustion chambers. The final step cleans everything from the gas tank to the fuel injectors or carburetor(s), including fuel pump and intake valves. Paying $100 for such a service is probably not uncommon, but you can pick up the kit (part #2630) for about a third of that. It only takes about 20-30 minutes to apply the kit, too. https://www.berrymanproducts.com/videos/view/how-to-video-berryman-products-3-step-fuel-system-maintenance-kit/