Yes, I did it a few years ago with moderate success trying to compensate for internal engine changes. Problem is that any change at a particular rpm seemed to upset the balance elsewhere. I guess it depends on what you are trying to do. Is the idle too lean/rich -- or is it complaints with driveability somewhere else in the rpm range? I don't konw if I'd mess with it if you're trying to clean up the idle with a stock motor that runs well otherwise. Try the knob on the ECU under the rear seat. If that's not enough, a simpler trick is to add a resistor in the coolant temp circuit to richen it up a bit. You can use a potentiometer to figure out what it likes, then find a resistor close to that amount to permanently solder into the circuit - or I suppose you could keep the pot so you can fine-tune it from the driver's seat. Before you go too far, you may want to try another good MPS to make sure the symptoms are the same. The diaphrams do develop leaks and it throws everything off.
