Briggs & Stratton Jets & Needle Valves
Keep your carburettor running smoothly with our comprehensive range of carburettor jets and needle valves for Briggs & Stratton engines. We stock main jets, pilot jets, and complete needle valve assemblies suitable for walk-behind mowers, riding tractors, and small engine applications. Our lawn mower carburettor components include brass jets in various sizes, rubber-tipped and metal needle valves, and complete seat assemblies for reliable fuel metering. Whether you need replacement Briggs & Stratton carburettor jets or complete Briggs & Stratton needle valve kits, we hold genuine parts in stock and sell worldwide for optimal engine performance.
Available Briggs & Stratton Jets & Needle Valves
Jet Main
498977
Briggs & Stratton
£6.50
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Jet Main
592792
Briggs & Stratton
£7.70
In Stock
Main Jet
710881
Briggs & Stratton
£18.05
In Stock
Jet Main
84001986
Briggs & Stratton
£8.20
In Stock
Jet, Main
791405
Briggs & Stratton
£9.70
In Stock
Main Jet
698788
Briggs & Stratton
£10.70
In Stock
Jet Main
84002021
Briggs & Stratton
£8.20
In Stock
Jet Main
84007560
Briggs & Stratton
£7.95
Available
Main Jet
591936
Briggs & Stratton
£8.20
Available
Jet Main
597547
Briggs & Stratton
£8.20
Available
Jet, Main
84001966
Briggs & Stratton
£8.20
Available
Jet Main
699897
Briggs & Stratton
£7.70
Available
Frequently Asked Questions
How do I know if my carburettor jets are blocked?
Your mower will typically take multiple pulls to start or fire briefly then die immediately. You might notice the engine starts with carburettor cleaner sprayed in but won't run on petrol alone. Under load, the engine may lose power or stall completely. Black smoke from the exhaust or dramatically increased fuel consumption also indicate blocked jets. These symptoms occur because old fuel leaves varnish deposits in the tiny jet passages, starving the engine of proper fuel flow.
What's the difference between the main jet and pilot jet?
The pilot jet controls fuel at idle and low speeds up to roughly quarter throttle, whilst the main jet regulates fuel flow from quarter throttle through to full power. Both work together to provide smooth running across all engine speeds. If your mower idles roughly but runs fine at full throttle, suspect the pilot jet. Conversely, if it idles well but bogs down under load, the main jet likely needs attention or cleaning.
Can I clean jets or must I replace them?
Most blocked jets can be cleaned successfully using carburettor cleaner spray and compressed air. Remove the jet, soak it in cleaner, then carefully clear the passages with a thin wire or torch tip cleaner—never use anything that damages the brass. If the jet remains blocked after thorough cleaning or shows physical damage, replacement is necessary. Always inspect jets under good light; even tiny scratches or deformities affect fuel metering and engine performance.
Why does petrol leak from my carburettor after the engine stops?
A stuck or worn needle valve is the usual culprit. The needle valve opens and closes to maintain proper fuel level in the bowl—when debris gets trapped on the needle seat or the rubber tip wears down, fuel continues flowing and eventually overflows. This often happens with equipment that's been stored with old fuel. Try draining the bowl and flushing fresh fuel through first. If leaking persists, replace both the needle and seat together for reliable sealing.
How often should needle valves be replaced?
Replace needle valves whenever you experience carburettor flooding, petrol leaking from the overflow, or fuel entering the engine oil. Even if the needle looks acceptable, worn rubber tips or grooved metal surfaces prevent proper sealing. As preventative maintenance, replace the needle and seat every 3-5 years or whenever rebuilding the carburettor. Always replace them as a matched set—mixing old and new components rarely provides adequate sealing and often leads to continued problems.