Usually runs fine at high speeds but occassionally will just die at high speeds unless I quickly choke it for 30 seconds then runs fine at high speeds again. Never Idles or runs at low speeds smoothly (Coughs and dies). This makes it hard to get in gear because it dies while I'm in nuetral. Smokes a lot on start up and a descent amount while idling. I've read some elses comments on a 70 hp doing the same thing and they relate to the carberator. Never really gone into a two cycle engine before, but if I were to take apart and clean the carberator I want to make sure I don't screw with any settings.