… Anyone who tries to adjust the float level on the carburetor with the original Rotax adjustment tools will probably throw the towel (or the screwdriver) in the corner after a short time.

I felt the same way and so, based on my experience as a motorcycle mechanic, I was looking for a practical solution. I was familiar with the usual adjustment and control tools and knew that none of them were suitable for the Rotax carburetor.

My requirement was:

• the gauge should be for the 912 and 914 Bing's,
• if possible, it should also be applicable for the 2-strokes,
• the float height should be readable in mm,
• show the difference between the two arms of the float suspension (this is the name of the rocker that operates the float needle valve),
• indicate the spread of the guide pins for the floats if the float chamber is distorted¹⁾,
• be robust and inexpensive.

So I sat down at my CAD program and, after a long series of measurements in my spare time, designed the float level gauge described here.

In the left picture you can see the millimeter division for the float level.
Here you can also see the difference between the two arms of the float suspension on the other side.

In the picture on the right the spread of the guide pins is checked. The thick line is the wear limit and the float chamber must be replaced. However, this actually only occurs with the 914 carburetor, as the float chamber is distorted by overtightening the central nut and the pins move outwards.