Which Rotax engines are fuel injected?

You are correct that the letter "i" following the engine model number indicates that the engine is fuel-injected.

It's important to note that not all carbureted engines are equipped with carb heat. However, they do have a choke knob, which is used to enrich the fuel mixture during engine start-up or in cold weather conditions.

Rotax-Owner wrote:

You are correct that the letter "i" following the engine model number indicates that the engine is fuel-injected.

It's important to note that not all carbureted engines are equipped with carb heat. However, they do have a choke knob, which is used to enrich the fuel mixture during engine start-up or in cold weather conditions.

Thanks! So the i is for injected. What does the S stand for?

How does a carbureted engine prevent carb ice without a carb heat knob?

Rotax engines are NOT Continental or Lycoming engines.

They have CV carbs ON TOP of the engine and are far more resistant to carb icing than the old engines

Therefore many people do not bother with a carb heat system and get away with this perfectly OK

However they are resistant not immune so if you live or fly in a place where moderate carb icing conditions often exist then there are aftermarket carb heat systems

I live in such a place however still only about 50% of the Aircraft operating here have a carb heat system....so it depends on how you fly as well. The local club aircraft never had a carb heat system and we flew several thousand hours with out a problem, them one day a Student reported a vibration that "sounded like" carb icing so we put carb heat on as a precaution.

again our experience with the old engines does not translate to the Rotax engine well

I believe the "IS" stands for "Injection System"

Regards

Good points. Thanks, Glenn. I flew behind a Continental O-200D before my fuel injected Rotax, and carb ice was absolutely a constant worry. Even flying around Florida it wouldn't be too hard to get carb ice. It was basically an ice maker. And it wasn't even equipped with a sensor to tell you when you've got ice so it was just a mystery and you'd have to pull carb heat every so often just to see if you had the symptoms of melting ice. Assuming you wanted to catch it early. If you didn't care about catching it early, you could always just wait until your engine started running rough. ? But I hated the fact of never knowing if carb ice was building or not. That made me never want to own another carbureted aircraft. But you make a good point that not all carbureted aircraft are like that.

It can be confusing, but here it goes!

The "iS" in the engine designation stands for Injected Series. However, in the case of the 912ULS, the "S" represents the 100hp version, while "UL" stands for Ultralight. The 912F is certified according to the FARs (Federal Aviation Regulations), and the 912A holds the European JAR certification.

Below is the breakdown:

• 912UL: Uncertified 80 hp (Carbureted)
• 912 A: Certified to JAR 22, 80 hp (Carbureted).
• 912 F: Certified to FAR 33, 80 hp (Carbureted).

• 912 S: Certified to FAR 33, 100 hp (Carbureted).
• 912 ULS: Uncertified, 100 hp (Carbureted).
• 912 ULSFR: Uncertified French Authority specification (90 hp). Same as the 912ULS, but with limited maximum RPM and blue valve covers.

• 914 UL: Uncertified, 115 hp (Carbureted).
• 914 F: Certified to FAR 33 (Carbureted).

• 912 iS: Uncertified, 100 hp (75 kW) with fuel injection and an electronic engine management unit.
• 912 iSc: Certified, 100 hp (75 kW) with fuel injection and an electronic engine management unit.
• 912 iS Sport: Uncertified, with larger aluminum airbox, longer intake runners, and eco-mode when operated below 97% power setting, with direct fuel injection and an electronic engine management unit.

• 915 iS A: Non-certified, with fuel injection and an electronic engine management unit.
• 915 iSC A: Certified, with fuel injection and an electronic engine management unit.
• 915 iS C24: Non-certified with 24-Volt system, with fuel injection and an electronic engine management unit.
• 915 iSC C24: Certified with 24-Volt system, with fuel injection and an electronic engine management unit.

• 916 iS A: Non-certified, with fuel injection and an electronic engine management unit.
• 916 iSC A: Certified, with fuel injection and an electronic engine management unit.
• 916 iS C24: Non-certified with 24-Volt system, with fuel injection and an electronic engine management unit.
• 916 iSC C24: Certified with 24-Volt system, with fuel injection and an electronic engine management unit.