Briggs & Stratton Flywheels
Our Briggs & Stratton flywheels provide essential engine momentum, cooling, and ignition functions for lawn mowers and small engines. Engine flywheels store combustion energy, house magnets for ignition systems and charging, and feature cooling fins for heat dissipation. We stock genuine Briggs & Stratton engine flywheel assemblies, replacement flywheel keys, and compatible parts for all engine series. Small engine flywheels require proper installation with correct torque specifications to prevent key shearing and timing problems. Lawn mower flywheel components include integrated magnets, starter ring gears, and precision keyways. We hold worldwide stock of Briggs & Stratton flywheels and sell globally with rapid despatch.
Available Briggs & Stratton Flywheels
Flywheel
590544
Briggs & Stratton
£42.50
In Stock
Flywheel Key
222698S
Briggs & Stratton
£2.95
In Stock
Key Flywheel
796335
Briggs & Stratton
£3.15
In Stock
Cup Flywheel
593960
Briggs & Stratton
£6.20
In Stock
Flywheel Fan
796201
Briggs & Stratton
£47.95
In Stock
Puller Flywheel
19203
Briggs & Stratton
£11.67
In Stock
Key Flywheel
797286
Briggs & Stratton
£3.90
In Stock
Flywheel
591759
Briggs & Stratton
£126.30
In Stock
Fan-Flywheel
691346
Briggs & Stratton
£19.70
Available
Flywheel Assy
594054
Briggs & Stratton
£54.10
Available
Flywheel
590420
Briggs & Stratton
£58.80
Available
Guard Flywheel
793756
Briggs & Stratton
£7.65
Available
Frequently Asked Questions
What causes a flywheel key to shear and what are the symptoms?
Flywheel keys shear when blades strike immovable objects, creating sudden crankshaft stoppage whilst the flywheel continues rotating. Insufficient torque on the flywheel nut (should be 45-50 ft-lbs) also causes keys to shear gradually. Symptoms include hard starting, engine kickback, backfiring through the carburettor, and poor performance. The soft aluminium key protects expensive engine components by absorbing impact damage. Always inspect the flywheel key after blade strikes and torque the retaining nut properly using a torque wrench.
How do I safely remove a stubborn flywheel from the crankshaft?
Never pry or hammer directly on the flywheel—this damages components and cracks cast iron flywheels. Use a proper flywheel puller tool that threads into pre-drilled holes on the flywheel. Thread the flywheel nut flush with the crankshaft end for protection, install the puller, then tighten evenly whilst tapping the crankshaft nut sharply with a hammer to shock the flywheel loose. The tapered fit between crankshaft and flywheel creates tremendous friction—pullers apply even pressure without damage. Penetrating oil helps on corroded assemblies.
What is the correct magneto air gap and why does it matter?
The magneto air gap between ignition coil legs and flywheel magnets should be 0.010 inches (0.25mm) for most Briggs & Stratton engines. Incorrect gaps cause weak or no spark, preventing starting. Too large a gap weakens the magnetic field; too small risks coil contact with the spinning flywheel. Set the gap using a feeler gauge—loosen coil mounting bolts, rotate flywheel so magnets face away, insert gauge, allow magnets to pull coil down, then tighten bolts and remove gauge.
Can I repair broken flywheel magnets or must I replace the entire flywheel?
Broken or detached flywheel magnets typically require complete flywheel replacement for reliability. Whilst temporary repairs using high-temperature epoxy (JB Weld) sometimes work, they often fail under vibration and heat. Missing magnets create imbalance causing severe vibration, damaged seals, and potential crankshaft damage. Interior magnets power the charging system; exterior magnets trigger ignition timing. Never operate with missing magnets—imbalance ruins bearings and seals. Professional replacement ensures proper magnet polarity, positioning, and flywheel balance for safe operation.
Why must flywheels be installed with specific torque and what happens if undertorqued?
Proper flywheel torque (typically 45-100 ft-lbs depending on engine model) creates friction between the tapered crankshaft and flywheel hub. This friction—not the key—drives the flywheel. The key only positions it for correct ignition timing. Undertorqued flywheels slip on the crankshaft during starting or under load, shearing keys repeatedly and destroying timing. Always use a torque wrench and the correct domed washer. Clean mating surfaces of oil or grease, which reduces friction and causes slippage even when properly torqued.