The high velocity air flow means a stronger vacuum at the needle jet for more precise metering, better throttle response.. Needle Jet - (389)Q-2. Throttle replacement valve Cutaway - 4.0. Air Jet - 2.5.
Needle replacement valve - 3.3. Choke Type - Button Free to the contiguous United States consisting of the 48 adjoining U. On the continent of North America. Photos are for reference only. Actual product may differ from the item shown in photograph.