MIKUNI NEEDLE JET 244-AA5.
The needle jet is the main fuel passage to the main bore of the Mikuni carburetor.
Depending on the inside diameter of a specific needle jet, this will also affect the function of the needle.
Needle jets and needles act together as the main system in controlling the amount and mixture of the fuel which is drawn in mid-range 1/4-3/4 throttle operation.