I thought Perry pumps were only designed for use with Perry pumper carbs. I tried one with a stock carb on an O.S. 40 and ran way too rich through mid range. After looking at their website It seems as though they make regular carbs and special ones for running with the pump. I ended up buying a Perry carb for the pump and it worked beautifully. You may want to do more research if you have running problems when you start it.

Max