Rotax 912-UL Repair Manual

Start tightening-screws
beginning with
the Allen
screws
M8 in middle
of crankcase
and
continue crosswise
outwards.
I ATTENTION:
Don't
turn over crankcase
prior
to tightening screws,
to
prevent
possible
passage
ofoil
to sealing
face!
To
achieve
the uniform
spreading of
the sealing compound
and to w:urant
the correct surface
pressure,
the 2
studs M8x291
as well as stud Ml0x225 have
to
be tightened, too, by
utilizing
appropriate distance
tubes
on
M8
studs
and the
listed 2
distance sleeves on M10
stud.
Tightening
torque: MlO
=
40
Nm
(350
in.lb.)
-
M8
=
25 Nm
(220
in.lb.)-
M6
=
10
Nm
(90
in.lb.)
The tightening
of crankcase
screws must
not result in
any offset
on the sealing face for ignition
cover and
gearbox
cover.
Check
for
easy
turning ofcrankshaft after
tightening of screws.
Ifnot
turning
freely,
dis-assemble,
find
cause
and
rectify.
7.2)
Piston
and cylinder
Forengines
certified
to
JAR 22, set
up dimension
sheet
for
cylinders
and
pistons
(see
chapter 1I).
Remove
service screws
MlO and M8.
Check
tightening torque 8 Nm
(70
in.lb.)
on
cylinder
studs
M8x20l
andM8x29l,
if needbe,re-torque.
Pistons
are off-centered
and
have
to be fitted with
zurow on
piston
top towards
prop-shaft,
thus on
cylinder
I
and 3
off-centering
downwards,
and
on
cyli
nder 2
and
4
off-centerin
g
upwards. Piston
is off-centred
by
I
mm.
Pistons without
iurow
or with arrow not visible
any
more, have
to be measured
for
clarification.
At
fitting
of
piston
pin
apply MOLYKOTE
G-N
paste
to
pin
as
well
as to
con-rod small
end and
piston pin
bore.
Fit
piston
pin
using
guide
pin
(sliding
frt). Always
fit
new
circlips, using
pusher
877 016.
Install
circlip with
gap
in
6 o'clock
position,
to maintain
tangential
force
of circlip.

Rotax 912-UL Specifications

General

Displacement	1211 cc
Bore x Stroke	79.5 mm x 61 mm
Compression Ratio	9.0:1
TBO (Time Between Overhaul)	2000 hours
Engine Type	4-cylinder, 4-stroke
Power Output	80 hp
Cooling System	Liquid/air-cooled
Fuel Type	Avgas 100LL or unleaded automotive gasoline
Oil Capacity	3 liters
Fuel System	2 carburetors
Oil System	Dry sump forced lubrication with separate oil tank
Reduction Gear Ratio	2.43:1
Max Continuous Power	75 hp (56 kW)