Hirth F-23
Introduction 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. It is manufactured by Hirth of Germany.
Development The F-23 is intended to compete with the  Rotax 503 and is differentiated from the Rotax powerplant by offering a horizontally-opposed cylinder layout. 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. Standard starting is recoil start. A belt reduction drive system, fuel injection, tuned exhaust and electric start are optional.The engine runs on a 50:1 pre-mix of unleaded 93 octane auto fuel and oil. Recommended time between overhauls is 1000 hours.The F-23 produces  at 6150 rpm and  at 5500 rpm.
Applications
Specifications (F-23)
References
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