Dellorto 9892 style/type. D31-RD SI Carb Idle Jet, made in UK.

·        Manufactured in England! Beware of other seller's products claiming UK origin as many are NOT! - always check the seller's "about" details!

·        65 Degree Venturi for High Performance (Standard 120 degree also available as D31; version without "RD")

·        Quicker Acceleration

·        Smoother Ride

·        Lower Tickover

·        Increased Fuel Economy

Our 65 degree high performance version is without the dot marking (position indicated on the image), which identifies the standard 120 degree version.

·        Idle Jet for Dellorto SI Carburettors

·    Sizes from 100-45 to 160-68 are available (see drop-down menu for current availability).

·       These are not OEM jets, but a genuine UK-made replacement for Dellorto style SI Carb Idle Jets.

·       KMT jets are high precision OEM replacement / after-market products.

·       Made in England on multi-axis Swiss automatic CNC lathes.

·    For SI Carbs in most of your Vespas

·       We also stock other Dellorto type jets.

ALL MANUFACTURED SIZES FOR D31-RD:

Part number guide - 1st number for air dia, 2nd number for fuel dia 

100-45, 100-48, 100-50, 100-52, 100-55

110-45, 110-48, 110-50, 110-52, 110-55

120-35, 120-38, 120-40, 120-42, 120-45, 120-48, 120-50, 120-52

130-38, 130-40, 130-42, 130-45, 130-48, 130-50, 130-52

140-42, 140-45, 140-48, 140-50, 140-52

150-42, 150-45, 150-48, 150-50, 150-52, 150-55, 150-58, 150-60, 150-65, 150-68

160-42, 160-45, 160-48, 160-50, 160-52, 160-55, 160-58, 160-60, 160-65, 160-68

Terms & conditions of sale apply - Returns accepted ONLY if packaging is unbroken and contents are pristine.

*DELLORTO brand name is for description purposes only - these are not original DELLORTO jets; they are a high-quality replacement.


Before contacting us, please note that KMT Products Ltd does not offer specific jet to carb / bike model compatibility or tuning/maintenance advice as a service, as this is not covered by our product liability insurance with any modifications which may have been made, and which we would not be aware of - you will need to contact a Shop or Dealer for assistance with this.

Whilst ALL our jet types are tested and approved, establishing the jet types suitability for each application is the responsibility of the buyer. Returns are accepted ONLY if the packaging remains unopened and in pristine condition.


Despatch time is usually within 24 hours (up to 2 to 3 days during peak periods).

Options: Royal Mail 1st/2nd Class, Tracked 24, or DPD Next Day (tracking included only where applicable).

Important Note: Selecting Tracked 24 or DPD Next Day guarantees the courier service used, not delivery within 24 hours of placing your order, as courier processing and collection times are out of our hands.

95% of orders arrive within 2 to 3 days, but please order early morning where possible to minimise unexpected courier delays! When orders come in for Tracked 24 we always try our best to post them that day (if in time) to minimise delay.

DPD example: Order placed Saturday, collection arranged Monday morning, collected Tuesday, delivered Wednesday (if not delayed).