How to reach the 109 HP allowed in FRANCE?

Hi Mr RTX,

The blue valves cover and the power limitation has been abandoned since years. We have "standard" 912 ULS, 100HP, green valves cover.

What it is new (since July 2019) it is the opt-out possibility to 525 kgs MTOW (ultralight equipped with parachute) and max power 109 CH (=80kW), minimum stall 70 km/h.

I understood that ROTAX is not interested to extend the power of their 912 ULS for such small market. So, why not big bore as ZIPPER or EDGE PERFORMANCE seems to offer with some success? Anybody has experimented these big bores?

Before you get all excited about another 8hp, be sure you are making use of all of the 100 that you already have.

The 912ULS makes 100hp at 5800rpm at WOT at Sea Level.

The WOT is easy enough and the Sea Level part is probably beyond reach.

The 5800rpm is where most people come up short.

If you can not get to 5800 rpm at some point during the flight, you are not using what you already have available.

Most operators will reduce throttle during cruise flight, but want all the climb they can get when they need it.

Make sure that you can make 5800 rpm at WOT at Vy in the initial climb.  It will fall off with altitude.

If you are seeing under 5600 rpm, flattening the prop will increase the climb.