Hi !
I can only fully agree with Tina: it depends on the motor and - as always in real life - circumstances You can influence or not.
I personally have only experience with Rotax 912 and 914 in gyros and I personally did not experience one single failure in 300 hrs. of recorded flight time.
At our homebase in Hungary/LHFM with 20 gyros of different make (MT03, MTsport, Magni M16, Magni M22, XENON, ELA 07S) all equipped with Rotax 912/914 in 2 years with a cumulated flight time of more than 2000 hrs. we had 3-4 incidents of a motor out in flight.
Two times the oil filter loosened in flight and went off ´cause it was not secured (or sabotaged) forcing an emergency landing. No casualties, not even slightest injuries.
One time the fuel-pump quitted forcing an immediate landing after T/O.
One time the motor quitted after T/O ´cause gyro was exposed to full sunlight and heat for hrs and a gas bubble plugged the gas-lines. Immediate landing took place, nothin´happened.
Other reported incidents not at our homebase that came to my knowledge: two guys accompanied an Off-Road-Rallye in Northern Africa with a MT03-gyro 2005 and they were filled up with Diesel instead of Auto-Gas by accident and had a harsh landing on rocks. No injuries.
In Germany pilots forgot to switch on the fuel-pump 2 (Rotax 914) causing 2-3 emergency landings after T/O (pilot error!).
Positive example: Otmar Birkner, the manuf of the MT03 and MTsport, went together with 3 other MT03s (Rotax 912/914) and special tanks (148l) all around Australia 2007 (7.000 miles) with no single engine out. Only incident: one fuel-pump was leaking in one gyro and had to be replaced.
Summary:
2-stroke air-cooled engines are more susceptible to failures than 4-stroke water-cooled because mostly of thermal problems in hot and humid weather conds. This is why Hirth-engines of older make have a "bad taste" here in Europe although it is mostly a cooling air intake design-problem by the aircraft manuf and/or lack of proper maintainance rather than by the motor itself.
In most serial prod. gyros (2-seat) You will find Rotaxes 912/914 like in most other ultralight and light aircrafts (FW) which are the market leader with an outstanding safety record for their reliability. But they are also the most expensive ones (actually there is NO single argument for a prizing triple or double the prizing of a SUBARU EJ-engine that was ORIGINALLY BUILT AS AN AIRCRAFT-MOTOR AND ONLY LATER TRANSPLANTED INTO CARS !!! which is mostly unknown and mostly thought to be vice-versa !)
To prevent In-Flight-failures of the engine by pilot error (having not done a meticoulous preflight-check IS a pilot error!) You have to check engine before flight:
1. any parts (oil-filter, tubing, radiators, wires, ign-plugs etc.) fixed and secured? No loosening parts ?
2. any leaks observed ? (this is why You have to CLEAN Your gyro carefully before flight thus enabling You to see upcoming leaks BEFORE they cause engine-failures.)
3. enough lubrication-oil ?
4. tanks filled properly for planned flight ?
5. before start-up of the motor: are both ignition-circles switched on ? Is fuel-pump 2 switched on ? CHECK !!!
6. Proper warm-up of the motor before flight (in this phase LISTEN to Your motor: it speaks to You. After 20-30 hrs of flight - like in a car - You will know how the motor has to "feel" and sound.
7. Check ignition-circles
In-Flight: check motor parameters (oil-temp, cooling-temp, PSI, exhaust temp) regularly, again: listen to Your motor ! In most cases (NOT IN ALL as You can read on this brilliant forum !) Your motor will tell You when it starts to feel not "healthy".
In most cases the pilot´s senses are finer than the instruments, so if You feel that Your motor does not feel well better not T/O or do a planned out-of-apt- landing ("security-landing") to check. (very easy with gyros!)
So I hope I could have given You some trust in motors but always have in mind: there is NO flight-engine in this world that could not quit suddenly and there will never be ! In gyros this is mostly no problem ´cause it is easy to do a safe emergency landing (as discussed in another thread concerning tree-top and water-landings) but it will always be YOUR responsibilty to plan Your flight-path every single minute in a way to provide safe emergency-landing.
For big water-areas - as Tina already pointed out - that means to fly close to the coast line and/or in case of crossing the area to do it at it´s narrowest landmark at a safe flight-level according to the glide-ratio of Your gyro (in general 1:3 - 1:4 which means if the water crossing is 3 miles You have to fly 1 mile high)
Last: do not build up fears and do not try by force to find arguments against gyroing ! THERE IS NONE ! It´s the safest and most enjoyable aircraft in the world (again: if flown properly). Once You are an experienced gyroist (after 100 hrs. recorded flight time) NEVER loosen Your discipline at preflight check and in-flight. Most pilot-error-accs occur then ´cause of "routine". There is no "routine". Every single flight is unique and wonderful even after 1000 hrs. !
Angelo
