Hi Chris,
I have been interested to see the comments regarding running rich at
altitude. I have 1100 hours on my XS mono, N262WF, with the 912ULS
engine. The engine is unmodified and I have had zero issues with running
rich during that time. Also the engine has never missed one beat.
A few comments :-
* My flying is typically a mix of recreational trips and visits to
local flyins plus flights to Sun N Fun (8 times) and Oshkosh (10
times). Local flying is usually done at part throttle and averages
about 4 gallons an hour door to door. My longer airshow trips are
normally done by climbing to get to smooth air, usually above 5,000
to 6,000 ft., I then set full throttle at 5500 rpm with my Whirlwind
C/S prop. In the summer, I often have to fly higher to stay above
the tops of towering cumulus and occasionally I get to 11,500 ft.
* During my early test flying, I did a check on my Service Ceiling. I
loaded the plane up to gross with a full tank and borrowed some
oxygen gear. At 16,000 ft., the plane was still going up at 200
ft/min so I was happy with that.
* The bottom line is that I have had absolutely no problems with rich
running. The engine has never missed a beat and the CHT's and EGT;'s
have always been in spec. The condition of the plugs at routine
replacement has always been good. At the last condition inspection,
my cylinder leakdown numbers were 80/80 on 3 cylinders and 78/80 on
the fourth.
* I did consider installing a Hacman package a long time ago when I
saw some discussion on the subject. After consideration I chose not
to do this due to the high amount of administrative work and knob
twiddling required for this to run satisfactorily. It also will kill
the engine if leaned out too far and that was unacceptable for me..
* With my C/S prop, all my flying is done at rpm's between 5,000 and
5,500.
* I note that my Rotax Operators Manual specifies - /The engine
allows operation with fully open throttle over the whole r.p.m.
range without limitation. But full throttle performance above 5,500
r.p.m. is limited to 5 minutes./ I comply with that. I also see
nothing in the manual which suggests that rich running is a concern.
Cheers, John
Mooresville, North Carolina
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S/ubject: Europa-List: Question about cruise altitudes with a 912ULS
From: "n7188u" <chmgarb@gmail.com> Dear Forum Members, Quick question
for those familiar with operating the Europa with the 912ULS engine:
What would you consider would be the highest altitude for normal
cruising with this engine. Read "normal" were the engine is not running
overly rich and causing other issues such as fouled plugs? Yesterday I
did a fairly long cross-country around Florida (about 3.5 hours total)
and on the return flight I was getting beat up by turbulence at 5,500
feet (can the Europa be rough on turbulence or what??). I understand the
912 is still happy at 5,500 but what about higher altitudes. I put up
with the turbulence. Rather silly since I could have just tried to go up
to 7,500 feet) but not knowing if the engine starts running too rich to
be happy I just put up with it. Best Regards, Chris/
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