Blower: Blows White Smoke From Exhaust

The cylinder in your leaf blower houses the piston and allows it to perform the proper function. If you notice that your leaf blower is emitting white smoke, there could be an issue inside the cylinder. As previously noted, a damaged piston ring could be the culprit. The piston rings create a seal to the cylinder wall to contain the combustion gasses and create the compression in the cylinder that operates the engine. The rings and the cylinder work together to form this seal. The ring doesn’t touch the cylinder; rather a thin film of oil separates it. The rings and the cylinder can be damaged either by dirt (which acts like sandpaper, wearing the ring and cylinder) or by lack of lubrication (which allows the metal ring to meet the metal cylinder, causing galling). Once this damage has occurred, the gap between the ring and the cylinder is increased. This leads to excess oil being allowed into the combustion chamber, and it can burn off as white smoke. Compression is also lost, and this can cause reduced engine performance. If your blower is emitting black smoke instead of white, it can be indicative of a separate issue. Please see our page on blowing black smoke for a list of parts that may be causing that symptom.

The carburetor won’t cause white smoke to come from the exhaust, however the carburetor can be affected by this problem. One cause for white exhaust smoke is too much oil in the gasoline of a 2-cycle engine. If there is too much oil in the fuel, it will tend to pool and accumulate in various locations in the engine. One of these is often the carburetor. The oil will plug the passages in the carb requiring it to be disassembled, cleaned, and a carb kit installed during reassembly. The carb kit consists of the parts needed to rebuild the carburetor, such as the diaphragm, reed valves, gaskets, and the metering needle.

A damaged or stuck piston ring in your leaf blower can cause the piston to malfunction. The piston ring seals the gap between the piston itself, and the engine’s cylinder wall. Without this seal, your leaf blower will have low compression, and as a result the engine may not start. Low cylinder compression because of a worn piston ring can cause your engine to blow white smoke. If you notice white smoke during a cold start, but it disappears as the engine warms up, it could be a result of carbon deposits around the piston ring. Replacing a stuck piston ring is a relatively easy job. Once you have access to the piston inside the cylinder, the piston ring simply snaps off and on.