Update on the "mystery ailment" of my MS201. Saturday PM just after Gunner & I & Dan & Gunner finished challenge races, Dan & I were having a discussion about MS200 vs. MS201. Dan brought out his 200T which ran like a AA fuel dragster, & I got my 201 which ran like a constipated cow!! While warming it up I said it wasn't running right. Dan, Mike, & Kevin all tried to help with the retuning after I took it from the beginning (started at idle & L adjustment & progressed to the H using both the tach & my ears). Nothing solved the problem!! I was flummoxed! After thinking about it for a few days, I thought there was something impeding the flow of fuel or exhaust. Where to start?? I thought I would replace the plug & fuel filter--just because! The plug looked fine, but I replaced it anyway. When I opened the fuel tank, it was 95% EMPTY!!! I replaced the fuel filter, filled the tank, & started it up. It ran perfectly!! Throttle response, acceleration, etc. couldn't have been better!! After a good warm up without putting it in wood, It tached at 13,800 with just a minor tweaking of the H screw. This is an ideal setting for this saw because the limiter cuts in at 14,000. Putting it in wood would up it to about 14,300 & make the tach bounce. This is exactly how I set it up after replacing the original coil, which was limited at 13,300, with the Stihl upgrade. Amen!!!