Mitsuzero our truck Mikuni carbutetors are a little different as well as other stuff a little different ~ try not too feel bad & don't give up ~ even after rebuilding my Mikuni carb new fuel pump all filters new dist cap rotor plugs wires all new MY TRUCK still has similar issues that you are experiencing ~ I think the often happening little miss mostly at low rpm in 2nd gear is fuel related because if I floor the accelerator it clears right up PLUS no other regular misfires happen when driving my truck ~ and the darn engine even has a brand new cylinder head too $÷&[,"#×%

Just try more trouble shooting testing etc & try not too spend to much $$ on parts if possible ~ don't give up these little trucks come in really handy & a new truck is so expensive ~ I use NON Ethanol gas (make sure the catalytic convertor is NOT plugged


Best of luck
George