Maximum engine performance depends on the fuel flow out of your fuel valve. Research has proven that, at a flow rate of only 28 ounces per minute, stock petcocks can starve even stock engines. If you modify your engine in any way, more fuel flow is required and must be supplied or you will suffer major tuning problems. Increasing the size of your jet will not  make more fuel available to you carburetor at higher RPMs. What is the solution? That's easy...Pingel® Fuel Delivery Systems. The Power-Flo™single outlet model has a flow rate greater than any other stock or aftermarket fuel valve. Available for your Triumph Bonneville, Bonneville T100, Thruxton 900, Scrambler 900, Bonneville America and Speedmaster. Required minor modification to the gas tank fuel delivery hole (petcock entrance). Kit includes gasket, mounting plate and your choice of round or hex Pingle Pro-Flo Petcock.