912UL fuel line & fitting size clean up (video)

 Coolant

Oetiker clamps for 360 degree clamping.

https://www.amazon.com/AKIHISA-300pcs-Single-Hose-Clamps/dp/B0DJXSLHZK/ref=sr_1_1_sspa?dib=eyJ2IjoiMSJ9.nbm_ptsK-kfbsUEDLYySPG_aMvn9PHU4HkXKmroA1cOzmKpF-OY1KUXsgGmxI-U4dOWCB_vzFo6uMRCm7mGBAYboWxoIQn6hkTEWtPmASYCNDNq1qDuDN9H7x71A6C4bEcGAc_qO1JnWMmIo9j6dEbrT8F0FvIXXxHUq8KB6KQAGrNUAQMOFD1YubKgE0gkpUz-wDX3nFdqkAdLU1BGvEW-K4DLmKSu80MiLFiD-qP8.Eev01NVlxn7k0eXPJYiYKIC_xgBHrasiG2XOl7c2GcA&dib_tag=se&keywords=single%2Bear%2Bhose%2Bclamps&qid=1766196750&sr=8-1-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&th=1

Dan Deckert wrote:

Oetiker clamps for 360 degree clamping.

https://www.amazon.com/AKIHISA-300pcs-Single-Hose-Clamps/dp/B0DJXSLHZK/ref=sr_1_1_sspa?dib=eyJ2IjoiMSJ9.nbm_ptsK-kfbsUEDLYySPG_aMvn9PHU4HkXKmroA1cOzmKpF-OY1KUXsgGmxI-U4dOWCB_vzFo6uMRCm7mGBAYboWxoIQn6hkTEWtPmASYCNDNq1qDuDN9H7x71A6C4bEcGAc_qO1JnWMmIo9j6dEbrT8F0FvIXXxHUq8KB6KQAGrNUAQMOFD1YubKgE0gkpUz-wDX3nFdqkAdLU1BGvEW-K4DLmKSu80MiLFiD-qP8.Eev01NVlxn7k0eXPJYiYKIC_xgBHrasiG2XOl7c2GcA&dib_tag=se&keywords=single%2Bear%2Bhose%2Bclamps&qid=1766196750&sr=8-1-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&th=1

Yeah! Good product but not easy to use when away from home (tools) and the single ear type can not be reused.😈

I have recently completed a full engine install with a 912A2 engine and found the fittings a nightmare. The original fittings on my engine were all AN and (I'm only guessing here) that there must be a reason why certified aircraft use AN instead of garden hose barbs  :-)

Following recommendations from others, I used all stainless and fire sleeved teflon hose with firesleeve and AN fittings. These were made and pressure tested for a very reasonable price by a speed shop. Most fittings are stainless but some are alu which I don't really like.

Some of the Rotax connectors such as the fuel pump and oil outlet from the engine could be bought as AN fittings for about the same cost of a CNC machine to remake them and the AN carb fittings were unavailable so on both occasions, I reused the existing brass ones.

The oil tank fittings have been changed from the old engine and currently here, only the barbed fittings are supplied… which it's not recommended to use with teflon hose so I reused the old oil tank top.

It would surely help if Rotax charged a similar price to other suppliers of small brass fittings… say $6 or $16 instead of $165.

If you use AN fittings for fuel and oil, you don't need to worry about hose clamps. I like Cobra clips because you can fit and remove them with pliers if you don't have the proper tool.

Obviously, this is a personal opinion but barb fittings just look wrong on an aero engine! On the other hand, Rotax should have done their homework and the coolant fittings make perfect sense so maybe I am overthinking this.

Hi John

On oil tank, oil cooler, fittings they are available in AN.  In the USA and all certified engines from Rotax the fuel system and oil lines are all AN (UNF is the term Rotax uses)  There is a slight difference in AN to UNF (or JIC is another term for the same type). The AN fittings have a superior thread peak and valley to the threads that leaves them with about a 20% stronger part.  The thread pitch and sealing surface, 37 degree face, is the same. You can see these fittings in the illustrated parts catalogue from Rotax. 

For homebuilders these are easy to source from automotive speed shop suppliers.  

The simple reason these are not used in the cooling system is the relatively low pressures and the size.  An AN fitting with a 25mm size would be extremely heavy.  This is why it was never a consideration for Rotax. 

Cheers