This is what the petcock looks like for your Puch. It should come out pretty easily just a little twist at the end. When I pulled my petcock out there was a bit of remanence of a seal. When you put the valve back on use some lock-tight around the threads. When you have the petcock out get a small screw driver out and check the bottom of your tank I found about a 1/4 inch of rust flakes in my tank that had been clogging up my filter. Also I found that the threads on the nut that connect to the petcock thread backwards.