Help! Engine Smoke

A lot of friends come to me with questions about their generator, snow blower, and lawn mower engines. Every so often, I’ll feature answers to my most-received small engine questions.

Help! Smoke is coming out of my engine!

Pause. What color is the smoke?

White or Blue Engine Smoke

If your engine is emitting white or blue smoke, it likely means your engine is burning oil. Maybe your crankcase has too much oil in it or you’re using the wrong oil type. According to the guide to lawn mower oil compiled by the folks at Briggs & Stratton:

• SAE 30 oil is best suited for operation at 40° F and higher (5° C and higher). It’s a good, all-purpose oil.
• 10W-30 works up to 100° F (-18 to 38° C) is better for fluctuating temperature conditions. This grade of oil improves cold weather starting, but may increase oil consumption at high summer temperatures.
• Synthetic 5W-30 -20 to 120° F (-30 to 40° C) provides the best protection at all temperatures as well as faster, smoother starts.
• 5W-30 is best for cold conditions—use it in your snow blower!

Other possibilities include a crankcase air leak, busted head gasket, or worn cylinder. TroyBilt has a great guide explaining how to troubleshoot this issue further.

Black Engine Smoke

Adjust your carburetor! Check out this video on how to adjust a carburetor on a Tecumseh engine.