thanks guys - yes, using the recommended plug - actually got it from the dealer, as I stopped to get new fuel filters, etc. early on in the troubleshooting process. I've swapped back and forth from the original plug, to the new plug or old plug, no change in behavior....so I just have the new plug in now, with the new coil and have spark again. Saw starts on choke - sounds rough, won't idle, I can keep it running by feathering the throttle and giving it gas when needed, but never gets close to idle...just dies. Sounds like carb related issues to me, but seems so odd that I would have these issues now. The saw ran flawlessly for the past few years. Ran 3-4 tanks full a week prior cutting up a stand of dead ash trees - no carb issues (before I lost spark). Lost spark, replaced with a new stihl coil, and now the saw won't run right and acts like carb issues/or maybe a vacuum leak, etc. Just hope I'm not dumping more and more money into it. The coil alone was $158 for the part....