I'm NOT a small engine guy but I'm turning into one just to keep the fleet running. The most common problems I'm finding are carburetor problems caused by debris from tank corrosion or just the affects of today's gasoline. I religiously run a mix of Seafoam, red HEET, and premium gas and even after running a carb dry and draining the tank, I still have carburetor problems. BTW, just because it "looks" fine doesn't mean it is.