How to reach the 109 HP allowed in FRANCE?

The 912ULS is a 100Hp (101.4 CH) engine.

Aviation is not the place to be making backyard modifications to eke out a little more power.

Reliability is way more important when you are in a vehicle that does not give you the option of randomly pulling over and getting out.

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Footnote:

CH = Cheval-Vapeur = literally Horse-Steam (Horse-Power)

109 French Cheval-Vapeur(CH) = 107.5 Imperial Horsepower (Hp)

Ronnie down at South Mississippi Light Aircraft builds a big bore Rotax that is around 109 hp. Lockwood thinks enough of the engine that they offer it as an option on their Air Cam.

There seems to be some really professional material around, like edgeperformance in Norway has on offer. 

It seems pretty obvious that the Rotax has great potential. To be honest, I am happy with my 80 horses but it has come to my mind occasionally how it would be to have 20 or something more under the bonnet.

At the same time I do not subscribe to „the more the better“. If you need to know how much the engine can handle be prepared to sacrifice one. Having said that, 10% extra doesn‘t seem too much to ask to me. And true, avoid backyard stuff.

A friend of mine added a nitrous oxide system to the 912uls on his Highlander its a great help getting off sandbars and clearing tree lines, do not know the added HP but the whole system only weighs 3.5lbs. 

Hello Eric

I fully understand your question as France limited the amount of HP that was allowed to be produced for ultralight. Rotax changed the color of the valve covers to blue the France Market and limited the max RPM to I believe 5500?

Regardless, if you have the 912ULS all you have to do to get 100hp is increase your RPM to 5800 RPM for take-off and you are good to GO!