Remove the fuel hoses from the tops of the float bowls, unscrew all four of the Philips head screws from each float bowl. Inside, you'll see a 10mm wide x 3/4" long valve that is bolted to the top that you just removed. Use caution when removing the top, so you don't mess with the Black round Float that hangs from the top. When you take the top off, you'll see the valve and be able to remove it with a 10mm wrench. Clean it up and inspect the rubber orr plastic tip on the inside peice of the valve to make sure it will reseat when put back together. It also might be time to just call Bruce at www.ztherapy.com He has everything you need. Valves, gaskets, etc, etc. Dave