I know Holly used to make replacements for several of the different Mikuni's.And they were slightly less then an origional rebuilt carb.I would try flow testing the fuel pump to see if it's the problem.If it is the pump?Sure,go ahead if you want the Trooper.Never actually changed a pump on that engine myself.But I've worked with a few of the automotive Mikuni carbs.And their both spendy and a pain with their many linkages,hoses,you name it.