Warranty doesn't mean shit if the dealer can't fix it anyway. Any moron can replace a carb. Yes, you usually have to remove the carb in order to shave the limiter. And yes, that means you have to pull the fuel line off the carb, as well as the choke and throttle levers.
If it's smoking a lot, what kind of mix oil are you using? I'm not familiar with Husky oil since we have no dealers around here anyway, but Echo oil is very good and Stihl synthetic (white bottle) is excellent. The standard Stihl oil (orange bottle) is garbage.
You might also try removing and cleaning the muffler screen, and perhaps making the muffler exit hole a little bit bigger while you are there. I've never run one in stock form but I seem to recall the mufflers are quite restrictive as they come from the factory. A few months running with the muffler all plugged up will cause a quick buildup of carbon and sludge. Open it up a little so the exhaust can get out and it can breathe a little. Your saw will be much happier, stronger and run cleaner.
