Jet Keihin Pilot #52 (FCR-MX) (4/Pkt)

The Keihin Pilot Jet #52 is a genuine replacement jet designed for use in Keihin FCR-MX flat-slide carburettors. Pilot jets govern fuel metering at idle and through the lower throttle range, making correct sizing essential for clean, consistent running.

Sold as a pack of four, this listing suits riders who are dialling in jetting across varying altitudes, temperatures or engine configurations and want a set of jets on hand for back-to-back comparisons or repeat builds.

• Genuine Keihin pilot jet sized #52
• Designed for Keihin FCR-MX flat-slide carburettors
• Controls fuel delivery at idle and low-throttle positions
• Pack of 4 jets — suited to tuning sessions or multiple builds
• Direct OEM-equivalent replacement

• 4 x Keihin Pilot Jet #52 (FCR-MX)

Install and remove jets using a flat-head screwdriver that fits the slot precisely — an ill-fitting tool can damage the soft brass head.
Do not use wire or metal picks to clear the jet orifice; compressed air or carburettor cleaner through the passage is the correct method.
Always clean the carburettor bowl and surrounding area before swapping jets to prevent debris entering the fuel circuit.
Do not overtighten when reinstalling — pilot jets are brass and the threads in the carburettor body are easily damaged by excessive torque; snug is sufficient.
When jetting for altitude or temperature changes, adjust one jet size at a time and test between changes to isolate the effect.
Store unused jets in a labelled, sealed container to prevent contamination and to keep sizes identifiable.
Inspect the jet orifice visually before installation; discard any jet that shows deformation, corrosion or obstruction that cannot be cleared with compressed air.