Small Engine Fastener & Torque Specs
OEM-referenced bolt sizes and torque specs for lawn mowers, riding mowers, generators, pressure washers, and other small engines. Find blade bolt torque, spark plug torque, flywheel nut, and engine fastener specs by equipment type and brand.
Common small-engine fasteners
The fasteners that matter most on small engines are the blade bolt or blade spindle nut, the spark plug, the flywheel nut, and the engine mounting bolts. Blade bolts on walk-behind mowers typically torque to 35-50 ft-lbs, riding mower blade bolts to 50-75 ft-lbs, and spark plugs to 10-15 ft-lbs on aluminum heads.
Why correct torque matters
A loose blade bolt is a safety hazard and a common cause of vibration and blade loss, while an over-torqued spark plug strips the soft aluminum head. Always use a calibrated torque wrench and replace any single-use crush washer on the engine oil drain plug.
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