PitStopUSA.com - Air Density Gauge

Air density or RAD (relative air density) is used as a valuable tuning tool to keep your jetting at its optimum. To use this gauge get a box of spark plugs and work on your jetting, reading the plugs as you go. When you get the motor just where you want it, record the air density or set the baseline on the digital air density gauge. Later - this could be later today, tomorrow, next week or next month - if the air density changes - and it will - you will instantly know how much to re-jet to keep that peak.