• Product Code: 312433362926
  • In Stock. FREE Delivery on all UK orders over £20
  • £136.71

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Needle Jet (Emulsion Tube) and Needle Jet Caps

Many newer bikes have very flat power and fuel delivery curves when used with the stock exhaust and air-box. When aftermarket pipes are used, the power curve is usually not flat. You find the need to lean out for low speed and richen up for top end, or leaner on the top end and richer at the low speed. In order to achieve full function and driveability, Dynojet develops shrouds or cap style nozzles for adjusting the upper or lower top end. They also have an effect similar to fuel injection by breaking up the fuel as it enters the air stream.

Fuel Needle

The design of the needle is where Dynojet spends most of its R&D time. The needle is designed to give the correct amount of fuel throughout the mid-range and is also designed to allow adjustment from groove 1 to groove 6 with little or no effect below 3000 R.P.M. Then with correct end dimensions, the needle will have little effect on the main jet regardless of needle position. This isolates all circuits from each other and ensures easy set-up of the midrange and driveability.

Main Jet

Dynojet develop our main jets to correctly serve two functions; static load and dynamic load. The static load is the fuel received through the main jet in the upper gears, where the tachometer is moving very slow. The dynamic fueling portion of the main jet is the amount of fuel received from the jet in the mid-range potion of the power. For example, you have a GSXR1100 G,H with #130 main jets. You then install #125 mains. After running the bike you notice the top end has improved but the mid-range doesn't pull as well. You then install #135 mains and you notice the mid-range is great but the top end is slower. This is a common compromise when using stock main jets and needles. If you install Dynojet 130 mains, you would get the mid-range power of the #135 and the good top end of the #125. This is because the Dynojet main has a venturi design more consistent to the engine's needs.

Main Air Jet

This jet allows air into the emulsion tube to mix with fuel being drawn up from the float bowl. It controls the amount of fuel which can be pulled from the float bowl into the venturi. The larger the size of the main air jet, the more air you get and less fuel. The smaller the main air jet, the more fuel you get and less air. Dynojet alters this only to achieve the flattest possible fuel delivery curve.

Pilot Circuit

This controls 100% of the engine idle and 25% of the transition onto the needle. Dynojet has found that the engine will idle with the standard pilot jet, with or without the air-box and with the slides and needles removed from the carburettors; therefore we never change the pilot jet. Doing so is proof that you are not using the other circuits correctly. Idle and off idle is controlled by the mixture screws and the float level which have the most positive effect below 4000 R.P.M. On some models the pilot air jet is changed to provide optimum fuel economy. Correct balancing of the carburettors also ensures a smooth idle.

Each kit is put together with full and comprehensive instructions which show step by step installation and testing procedures to ensure a perfect set-up every time. This is backed by free telephone support to Dynojet customers.

We only ship to the address on Paypal. If you require a specific address to ship the order to, please make sure that you enter this in the Paypal confirmation before confirming payment. We will not ship to any other address under any circumstances. If you have asked for a change in address please contact us as we will hold your item due to Ebay regulations only allowing us to send to the registered PayPal address.

We aim to process and dispatch your orders placed Monday - Friday; on the same or next day. Orders placed on the weekend and on Bank Holidays will be dispatched the following working day.

The majority of parcels are normally delivered between 1-5 working days but Royal Mail say it can take up to 10 working days to be delivered. If you have not received your item after 10 working days please contact us (please note weekends are not considered working days).

Next Day delivery can be arranged for an additional cost and must be paid for at the time of purchase. Cut off time for Next Day delivery is 2pm.

There is no Special Delivery service or Courier service on Saturdays, Sundays or Bank Holidays

All of our items are sent via Royal Mail/DPD/Interlink or the best available courier for your area. Although we have built an excellent reputation of delivering items before the estimated delivery date, sometimes items do get delayed by Royal Mail and this is beyond our control.

NOTE: Lost items can only be claimed from Royal Mail after 10 working days, which then we will take the necessary action. If you contact us before the 10 day period we may ask you to wait until the then before we take action.

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