The Bing carbs your referring to are auto-leaning as the slide and needle
move up and down based on air velocity (Constant Velocity carbs.)

They use a butterfly before the slide to limit air intake to control engine
power.

They worked very well on the R75/5 and newer BMW R motorcycles here in Arizona
where we have pressure altitudes from 1000' to 9000' foot on the ground!

Let me know if you have any other questions on the Rotax. I flew quite a bit
behind on in a Dimona Katana. NICE engine and plane.

--
Bart D. Hull

Tempe, Arizona

Check http://www.inficad.com/~bdhull/engine.html
for my Subaru Engine Conversion
Check http://www.inficad.com/~bdhull/fuselage.html
for Tango II I'm building.


Steve Robertson wrote:
I'm a longtime pilot who is getting interested in building a plane. I've
got lots of experience flying (and paying for maintenance) behind
LyContisuarus engines, so that's all I understand.

Some of the designs I'm interested in recommend the Rotax 912 engine.
These seem to come equipped with twin Bing carbs. As far as I can tell,
these carbs don't have a mixture control for leaning the engine at
altitude. Am I correct? If so, has this been an operational problem with
these engines? Has this proved to be a reliable engine?

TIA,

Steve Robertson
N4732J 1967 Beechcraft A23-24 Musketeer