I just bought this model today & put it to work as soon as i got it home. Did 3 & 1/2 hours mowing & used about 3/4 of a tank of fuel. The engine ran smooth & quiet & performed will. The safty cut out bar on the handle was a pain so i made a wire clip to clip the bar to the handle, when i need to stop the engine i flick the clip of the handle. No problems. When decreasing the rev's it pops & crackles. I think that is just in the tuning. I will run it until it needs a service & get it re tuned. Otherwise a good little unit.