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1. Clean and degrease the crankshaft end and mounting holes on the
crankcase before starting.
2. Using the Rotax fixation tool supplied in the Rotax tool kit lock
the engine up by installing the pin into the impulse hole, used to run the fuel pump. With
the pin in place rotate the engine, until it locks.
3. Install drive gear onto crankshaft end, with the lockwasher under
the head of the bolt, and the flat washer under the lockwasher. Torque to 45 FOOT lbs.
4. Install the rubber O ring (#3) into the back half of the gearbox
adapter plate, if necessary use dielectric grease to hold ring in place.
5. Position back half of gearbox (#1) onto crankcase. Apply loctite
#242 to threads of bolts (#4) install 4 allen bolts bolts and torque 30
FOOT lbs.
6. Install the rubber O ring (#3) into the front half of the gearbox
adapter plate, if necessary use dielectric grease to hold ring in place.
7. Install back half of gear box housing.
8.Install gasket - make sure gasket is not damaged.
9. Install front half of gear box housing and secure with bolts/nuts
and lockwashers. Use loctite 242 on threads and torque to 195 INCH lbs.
10. Fill gear box with 90 weight oil until oil runs out the lower of
the two side plugs.
11. Tighten then safety wire top and bottom plugs.
12. Tighten then safety wire vent cap and drain plug.
Rotax A Gear box updates:
Updated - Rotax gear, dog hub, washers, shaft.
Aircraft: All ultralight aircraft using the Rotax reduction drive.
Incident report:
We have several reported problems from pilots using the Rotax reduction
drive.
1. a hard to start engine, or an engine that will start but has a hard
time coming off an idle or runs very erratic at idle.
2. the gears inside the gear box disintegrating, especially on engines
using large radius propellers.
3. the gear box retaining bolts vibrating loose and or breaking allowing
the gear box to in one case come right off the back of the engine.
4. the output shafts on the gear box especially on the 65 hp engines,
severing, or the prop shaft hub cracking.
5. the oil slinger located on the end of the output shaft breaking and
then getting messed into the gears.
6. the loss of reduction drive gear oil during flight.
7. the stripping of the bolts used to attach the prop to the hub of the
gear drive.
Suggestions:
1. There was a problem on early Rotax gear drives where a series of
spring washers inside the gear box, over a period of time lost their
tension.
This in turn caused the engine to become hard to start, and would not come
off an idle. Rotax has an update kit which replaces the eight spring
washes, and spacers found in the old style gear drives with a new 12
spring washer system.
It is recommended that these spring washers be replaced every 150 to 200
hours and that the gear drive oil be checked periodically, and replaced
every 100 hours or yearly which ever comes first.
2. The problem with the gears shattering was also an early problem, and
there is also a retrofit kit, which replaces the gear with a stronger
gear.
3. The problem with the retaining bolts backing off was more common on the
3 bolt pattern adapter plates, the new engines are 4 bolt. This problem
was also caused by pilots who were reinstalling the gear box for whatever
reason.
In reinstalling the bolts on the 3 bolt system, there are two different
lengths of bolts. Both bolts will go in and appear to tighten the plate
against the housings. In fact the longer bolt is bottoming out in the
crankcase housing and is NOT tightening up on the adapter plate.
4. The aluminum hub cracking hub cracking problem were also corrected on
later model Rotax reduction drives, I am not however aware of a retrofit
kit for this at this time. The only suggestion would be to update to the
new style steel output shaft and hub.
5. The oil slinger problem has been eliminated by the removal of the
slinger completely. New model engines do not come with the oil slinger,
and the removal of them is recommended on older style gear drives.
6. The stripping of the prop bolts seems to occur when pilots have taken
off and reinstalled their props several times. Some pilot have reported
drilling out the holds using larger bolts, with locking nuts, and safety
wire.
Other pilots have simply gone to larger bolts and used the other bolt
pattern on the redrive. This problem is caused by the pilot over torquing
the prop bolts on installation. The recommended torque is 100 INCH LBS.
7. The gear oil existing problem can be cured simply by installing a very
small gas line filter on the top of the reduction drive vent cap using a
small piece of gas line and some clamps. It is caused by the prop creating
a low pressure area above the vent, siphoning the oil out of the gear
drive.
Rotax Engine Rebuilding Videos
Rotax engine rebuilding videos, each video is approximately 2 hours in
length and takes you step by step through the tear down, clearing, and
reassembly of a Rotax engine
Click
here for more information!
Click
here for proper A and B box preload procedure
Click here for gear box installation in pdf format
Rotax gear box updates -
click here for more information
Rotax manuals in pdf format
Rotax 2 stroke installation manual
Rotax 2 stroke maintenance manual
Rotax 2 stroke operators manual |
