Today while doing maintenance on my equipment I noticed that the flange that mounts the air cleaner to the carburetor is warped. This is a plastic piece that has a rubber boot on one end and attaches to the carb via 3 screws on the other. Mine was warped enough to cause contaminated air to get past and into the carburetor. Check yours immediately! Mine was warped so that there is a sizeable gap in the top of the flange to carb mounting surface. Please no redmax bashing people, just trying to notify other owners of the problem I have discovered.