I found a simple solution to the notorious Magnetti Marelli fast idle curse. After I did my engine mods the fast idle issue was happening all the time, much worse in cold weather. My theory is the engine runs cooler now with a better-breathing air cleaner and cam. I noticed it would idle fast after coasting down a long hill, then fix itself if running under a moderate load. The fast idle is controlled by the temp sensor in the chimney of the front cylinder (97 RK). I just bought a 2.5 mm allen wrench to keep with me. Next time it idled way fast (didn't have to wait long, it was doing it when I turned it off to buy the wrench!) I just dialled down the fast idle to where it was tolerable, maybe 300 rpm above normal idle. Now when it does it, I don't care, since it's not idling at 3000 rpm anymore! It does idle a little too slow when cold, I have to hold the throttle open a smidge when starting. But after about 10 seconds I can let it idle by itself. The fast idle screw is in front, on the throttle shaft. With stage 1 air cleaner it is accessible without removing anything.