Does anyone know the correct needle seat size (Also known as the float/needle valve) for a 88 YZ250 38mm roundslide Mikuni? I just ordered one that they say fits this carb, it is a 1.5...but the one in my carb is a 3.5. Which is the correct one and can someone explain the difference/performance aspect of the smaller/larger opening? With the 1.5 installed, it seems to be starving for fuel. While occasionally the 3.5 overdumps fuel causing flooding.