Why does my engine's RPM seem to fluctuate (runs rough)?

Many engine performance problems can be linked to maintenance issues such as stale fuel, dirty air filter, fouled spark plug, and deteriorated oil. A great way to help avoid these problems would be to perform an annual tune-up using a Briggs & Stratton Engine Maintenance Kit.

Engine hunting and surging at idle is usually caused by a fuel delivery, air leak, or governor system problem. Cleaning/overhauling the carburettor, adjustment of the governor, and/or changing the air filer may be required.

If you wish to perform this maintenance yourself, a good source for engine specifications and technical servicing information would be a Briggs & Stratton Repair Manual. The correct Repair Manual for your model engine is often listed in your engine's Illustrated Parts List. Repair Manuals are available for purchase from a Briggs & Stratton authorized dealer. Your Illustrated Parts List will also provide component part numbers specific to your engine's Model, Type, and Code that you may require.