Briggs & Stratton Ignition Coils
Genuine Briggs & Stratton ignition coils (also called armatures or Magnetron modules) generate spark for lawn mower and small engine ignition systems. We hold ignition coils in stock and sell worldwide. Modern solid-state coils replaced breaker-point systems after 1982, eliminating condenser maintenance whilst improving reliability. Common failures include heat-induced internal shorts causing engines to die when hot, grounded kill wires preventing spark, incorrect air gap affecting magnetic field strength, and weak flywheel magnets reducing coil output. Air gap specification ranges 0.010-0.014 inches between coil legs and flywheel magnets. We stock Briggs & Stratton ignition coils globally for all engine series.
Available Briggs & Stratton Ignition Coils
Armature Magneto
590454
Briggs & Stratton
£45.10
In Stock
Armature Magneto
595959
Briggs & Stratton
£55.45
In Stock
Armature Magneto
398811
Briggs & Stratton
£52.30
In Stock
Armature Magneto
591459
Briggs & Stratton
£38.40
In Stock
Armature Magneto
595554
Briggs & Stratton
£50.55
In Stock
Armature Magneto
796964
Briggs & Stratton
£48.05
In Stock
Armature Magneto
84003819
Briggs & Stratton
£48.60
In Stock
Armature Magneto
798616
Briggs & Stratton
£22.00
In Stock
Armature Magneto
591420
Briggs & Stratton
£43.50
In Stock
Armature Magneto
84005272
Briggs & Stratton
£35.10
In Stock
Armature Magneto
590781
Briggs & Stratton
£32.55
In Stock
Armature Magneto
595304
Briggs & Stratton
£50.55
In Stock
Frequently Asked Questions
What resistance readings indicate a faulty ignition coil?
Briggs & Stratton publishes no official resistance specifications—ohmmeter testing provides limited diagnostic value. Secondary winding (spark plug wire to ground) typically reads 2,500-5,000 ohms whilst primary reads near zero ohms appearing identical to closed breaker points. Infinite resistance (open circuit) confirms definite coil failure. However, coils passing resistance tests frequently fail under magnetic load during operation. Definitive testing requires spark tester (part 19368) connected plug wire to ground, spinning flywheel minimum 350 RPM observing spark window. Kill wire must disconnect eliminating false grounding preventing accurate coil evaluation.
Should I upgrade from breaker points to electronic ignition?
Single-cylinder engines with two-leg armatures accept solid-state conversion kit 394970 bypassing points and condenser eliminating maintenance. Kit installs between points and coil using existing Magnetron-compatible armature—unsuitable for three-leg armatures or Magnematic magneto systems (pre-1982 Model series). Electronic ignition provides consistent spark timing, eliminates point wear and condenser failures, improves cold starting reliability. Points engines before 1982 benefit most from conversion. Kit costs less than repeated points replacement whilst modernising ignition system. Original breaker-point systems remain serviceable when properly maintained with correct point gap and clean contacts.
How do I set the correct air gap when installing a new ignition coil?
Position coil mounting bolts loosely allowing movement, rotate flywheel magnets away from coil. Place 0.010-inch feeler gauge or standard business card between coil legs and flywheel rim. Turn flywheel until magnets align directly under coil—magnetic attraction pulls coil against shim automatically. Tighten both mounting screws whilst holding shim in position. Rotate flywheel removing shim—coil should clear magnets without contact. Common specifications range 0.006-0.010 inches for older engines, 0.010-0.014 inches for modern Magnetron systems. Gap too wide weakens spark, gap too narrow causes coil damage from magnet contact.
Why does my engine have no spark even with a new coil fitted?
Disconnect kill wire from coil spade terminal before condemning coil—grounded kill wires prevent spark mimicking coil failure. Kill wire connects coil to stop switch, seat switch, brake switch creating ground circuit stopping engine. Rubbed-through insulation, pinched wires against sheet metal, or failed safety switches ground kill wire continuously. Test coil with kill wire completely removed—spark appearing confirms wiring fault not coil failure. Check flywheel magnets attract screwdriver from one inch distance. Verify air gap 0.010-0.014 inches. Clean rust from coil laminations and flywheel magnets improving magnetic field strength.
Can ignition coils fail from heat causing engines to die when hot?
Heat-induced coil failure creates internal shorts in solid-state trigger circuits—coils work cold but fail after 20-45 minutes running. Internal transistor components break down under temperature stress causing intermittent spark loss. Engine dies suddenly, regains spark after cooling 30-60 minutes repeating cycle until permanent failure occurs. Test immediately when engine stops hot—no spark indicates thermal coil breakdown. Plugged cooling fins, improper kill wire connection to battery voltage, excessive engine temperatures accelerate coil failure. Heat failures worsen progressively—initial intermittent problems become permanent. Replace coil when heat-related spark loss confirmed through hot testing.