6bg6ga 271 #26 Posted July 31, 2017 16 hours ago, rmaynard said: So, it ran bad before the carburetor was changed, and it improved slightly but still runs bad afterwards. Makes me think that it's not the carburetor but a bad fuel delivery system, including the pump and fuel lines. I have seen fuel pumps that work erratically. Because the tank is higher than the carburetor, if the one-way valves in the pump are weak, fuel will flow through the pump and fill the bowl. Engine will run and a weak pump will keep trying to fill the bowl, but if the one-way valve discs are not sealing or the diaphragm is weak, the fuel volume can't keep up with the need. I'll give you that one. But before you rule on the fuel pump being bad don't you think the low and high speed adjustments could stand a look at? Share this post Link to post Share on other sites
