I now have an issue with my saw. It will idle after start-up and when I start running it and then release the trigger it is still in the throttle about half way. After five seconds it goes back down to idle most of the time. Or if it goes down to idle it takes the chain a few seconds to stop spinning like it is free spinning. I did a muffler mod a while back and re-tuned and it went fine. Before the new symptoms started I did a mild port on it. I took off the lip on the intake as it goes into the cylinder. I made it wider a small bit. I squared up the exhaust port on the top part and then polished it. After I did that I re-tuned and tested it. It ran awesome. The next day I went to show my girlfriend how well it cut and It lost power when I was in the cut. Not when it first loaded up about a 1/3 into a 30" log it would. I figured out that it was the crank case tube that goes to the carb, it wasn't on. I hooked it back on and then it started to do what I mentioned above (but it has power once again). I rebuilt the carb and it still does the same thing. The only thing I could think of is the L mixture setting. I am just at a loss. Sorry for such a long post but I figure more details the better. I will pick ya'lls brains to see if someone knows what is going on (or what I did wrong).