Use of 100 LL fuel on 914 F engine for long endurance

The 900 series engines are not designed to run on 100LL, they are designed for use with MOGAS. The lead can cause you problems if 100LL use is prolonged. If you look at the Rotax service manual it will offer guidance on reducing the service interval to help deal with the excess lead in 100LL.

This topic has been discussed many times within the forum. We have a search function on the R/H side of the forum where you can search for topics and see if they have been posted and discussed before.

We have seen very good results with the use of 100LL and the use of DECALIN or TCP fuel additive. If you are going to operate with 100LL then you should stick to the recommended maintenance procedures (use of 100LL over 30% of the time) and use TCP or DECALIN fuel additive. 

Links to DECALIN:

https://www.aircraftspruce.ca/catalog/appages/Decalin.php

Links to TCP:

https://www.aircraftspruce.com/catalog/appages/alcortcp.php

Below are some links to where this topic has been discussed before:

https://www.rotax-owner.com/en/general-tech-discussion/2744-use-of-100ll-fuel-in-912

https://www.rotax-owner.com/en/general-tech-discussion/418-90-octane-auto-vs-100ll

https://www.rotax-owner.com/en/912-914-technical-questions/1437-rotax-recommended-oil-change-interval-100ll

https://www.rotax-owner.com/en/912-914-technical-questions/8454-use-of-100ll-fuel-in-914

https://www.rotax-owner.com/en/general-tech-discussion/8312-can-i-blend-100ll-with-mogas-with-ethanol

Kevin Stewart wrote:

The 900 series engines are not designed to run on 100LL, they are designed for use with MOGAS. The lead can cause you problems if 100LL use is prolonged. If you look at the Rotax service manual it will offer guidance on reducing the service interval to help deal with the excess lead in 100LL.

Disagreed. Do you have Rotax 900 manuals reference or  service bulletins references regarding design on 100LL.

Both Fuel specix are same.

Engine design parameters and requirements depends on What?

Capt Siva,

 Kevin is correct the Rotax was designed to use Mogas.

It CAN use 100LL but as the documentation YOU PROVIDED says it adds extra stress on the engine, and should only be used if necessary and in some special suituations.

Kind regards

Glenn

If you strip down a 912 that has been run on 100LL you will see the excess lead deposited around the engine. It might be possible to control this with various additives but this was not the intent of the designers who expected owners to run it predominantly on MOGAS.