Ive got a cr125 shifter with a round dual sided Mikuni fuel pump. Currently the pump is supplying WAY too much fuel to the carb. The pump is set up to be a pump around and bypass the carb floats. Engine, carb, and fuel pump have all been rebuilt. Everything worked before the rebuilds. The carb is jetted to 165/52 with stock turns on the screws. Clip position has been set to the leanest to try and reduce the amount of fuel going through. The kart will start up after being cold and then will flood itself after about 20 seconds. Any questions or comments would really help. I cannot figure out for the life of me why this thing is flooding so much.
Not super familiar with the pump around setup, but could it be that the return circuit is not functioning properly? Maybe a result of not being plumbed properly?
For sure what Evan mentioned is pretty common. The return side can get kludged up with oil and lose some of its pumping efficiency.
Also there’s often a main jet placed in the actual fuel line to restrict/manage the flow on the return. That could be clogged too.
That is what I was thinking as well. My next step was to break down the fuel pump again. I rebuilt it with all brand new diaphragms and seals, so I’m not sure what could be going on with it. Both sides of the pump run from the same pressure line. Maybe there is some sort of clog on the return side. Thank you
Interesting, I haven’t seen that before. Maybe I am missing that. Any idea where I could find what that looks like?