The Hirth F-23 is a twin cylinder, horizontally-opposed, two stroke, carburetted or optionally fuel injected aircraft engine designed for use on ultralight aircraft.
The F-23 uses free air cooling and piston-ported induction, with dual Bing 34mm slide or optional diaphragm type carburetors.
The cylinder walls are electrochemically coated with Nikasil.
A belt reduction drive system, fuel injection, tuned exhaust and electric start are optional.
[1][2] The engine runs on a 50:1 pre-mix of unleaded 93 octane auto fuel and oil.