Here is the saw with the original carb back on it without doing anything to it other than cleaning it out. It was the pulse hose that was the problem. Next time I have a crappy idleing Stihl saw I will spray it down to see what happens. As for my cheap tachometer, it sucks. It works great at an idle and up until about 6000 -7000 rpm's. Sometimes it will go up to 10k 11k before it just drops back to 5600 - 5700. Even with the wire around the plug wire it does the same thing. I can't get to set the high jet with the tachometer. Until I get a decent one it is back to using my bad hearing to set the high end. I tried the tachometer on my 440, 268/272zp conversion and my newly acquired 394XP. It works the same way as it did on the Stihl saw.