Replacement petcock

I have a 1984 Gpz 1100 that I switched over to BS 34 Mikuni carbs. The problem I have is with the stock petcock. The flow is very poor and it does cause fuel starvation problems at wide open throttle .The petcock was meant to be used with a high pressure fuel pump. Has anybody had this problem? Is there a replacement petcock that I could use in place of the stock unit. Thankyou

Check out Pingel and Golan petcocks. They should have something that will work well. Ed

www.pingelonline.com/prodcat/fuel-valves.asp

www.golanproducts.com/fuel_valves.html