Needle Carb Fuel Mapper™

How to measure your carburettor

Needle in Slider Measurement

With the needle in the slider... how much of the needle is hidden in the slider body?

Place the circlip on Notch 1 (of any needle)
Measure 'x'

Place the needle in the slider.
Measure 'y' from the needle tip, to the base of the slider.
h = x - y

(the program calculates that for you... just enter x & y)


Carb Bore Height Measurement

Circular bore carbs - the height will be the stated carb size

Oval bore carbs - the bore height must be measured

1mm can be added to the bore height, if the slider rises above the bore at WOT
(WOT = Wide Open Throttle)


Atomiser Ring Depth

Usually the atomiser ring is at the same level as the base of the bore (= 0)
The Mikuni TMX has the atomiser below the base of the bore... perhaps other carbs also.

Using the vernier gauge depth prong:
Measure from the base to the atomiser ring.

If the atomiser bush is high (2 strokes like the drawing)... measure from the bush to the base
... then from the bush to the atomiser ring.

Subtract the short dimension from the long dimension = W