Parts for Briggs & Stratton 12S902-2139-B1: Cylinder Head, Gasket Set-Valves, Valves Parts

This valve retainer is an authentic replacement part for use with many types of small lawn and garden engines. The retainer valve helps to keep the lock valve spring on the valve. It is shaped similarly to a washer, which will fit over the top of the valve spring. The piece also helps to add space between the valve spring and the head of the valve. The valve retainer is made from metal, and it is a small piece. The retainer could become lost and need replacement when performing other maintenance on the engine's valves. The metal could also become corroded or break. In those cases, it will need to be replaced as soon as possible. This is a genuine OEM replacement part that is sold individually. The part can be used with many types of equipment including lawn mowers, snowblowers, tillers, pressure washers, edgers, leaf blowers, log splitters, and wood chippers. Compatible brands include Briggs & Stratton, Craftsman, Toro, Cub Cadet, Murray, Lawn-Boy, Snapper, MTD, Simplicity.

This is a durable metal valve tappet that is designed for use in small motor lawn equipment. It is attached to the push rod. The valve tappet takes the rotating motion from the camshaft and turns it into a linear motion for the valves to operate correctly. In some cases, the valve tappet can become damaged or break and will need to be replaced.If there is an issue with the valve tappet, a set of pliers will be needed to make the replacement. For safety, use work gloves and make sure the spark plug wire is disconnected before starting the replacement. The crankcase breather, muffler, and other components will need to be taken off to gain access to the valve tappet to replace it.This valve tappet is a genuine OEM replacement component directly sourced from the manufacturer. It is sold as an individual replacement part. It is designed to be used on lawnmowers, snowblowers, tillers, pressure washers, leaf blowers, generators, and chipper shredders manufactured by Briggs & Stratton, Toro, Cub Cadet, Lawn-Boy, Snapper, MTD, and Simplicity.

Spark plugs work by providing an electric spark in a combustion chamber, igniting the mix of fuel and air that allows the engine to turn and propel a drive shaft. Insulated with ceramic to make sure the electric charge flowing through it is properly discharged, the plug is screwed into the cylinder head. The movement of the piston sucks fuel into the cylinder until it reaches the optimum level, the compression triggering the spark plug to send a pulse that ignites the fuel and pushes the piston to the back of the cylinder. This process is repeated hundreds of times a minute in an internal combustion engine. Eventually spark plugs simply wear out, particularly if they are not properly gapped, if the fuel mixture is improper, or the engine is subject to excessive use. This plug is compatible with most lawnmowers, small engines, and pressure washers made by Briggs & Stratton, Cub Cadet, and Toro. The plug itself is a guaranteed OEM part and is sold individually.

The spark plug boot is a rubber piece that is responsible for connecting the spark plug to the spark plug wires and completing the connection. Spark plugs are necessary to create the engine spark that will start the motor in lawn equipment and other small engines. The boot holds the terminal and keeps everything protected from the elements and insulated so that it continues to work correctly. If the spark plug connection seems weak or if the existing boot is damaged, this replacement could provide the solution. This durable rubber boot will insulate the spark plugs and help any small engine run better. This spark plug boot replacement can be used with a number of Briggs & Stratton engines and is compatible with hundreds of different machines from Toro, Lawn-Boy, and Briggs & Stratton. This boot replacement is sold individually as a single piece and does not include the terminal or any other housing or materials.