BRP ROTAX 912 Series Reference manual

27 July 2019 Current valid documentation see: 73-00-00
Initial Issue www.flyrotax.com Page 1 of 13
Copyright - BRP-Rotax GmbH & Co KG. All rights reserved.
d06767.fm
SB-912-073 / SB-914-055
SERVICE BULLETIN
Replacement of circlip (carburetor) for ROTAX®Engine Type
912 and 914 (Series)
ATA System: 73-00-00 Fuel system
MANDATORY
1) Planning information
To obtain satisfactory results, procedures specified in this publication must be accomplished with
accepted methods in accordance with prevailing legal regulations.
BRP-Rotax GmbH & Co KG cannot accept any responsibility for the quality of work performed in
accomplishing the requirements of this publication.
1.1) Applicability
All versions of ROTAX® engine types 912 and 914 Series are affected if at least one of the follow-
ing criteria applies:
Criterion A) Engine serial number:
NOTE: Engine with S/N higher than the range listed above, have already been inspected
during serial production and are equipped with the carburetor circlip part no. 945786.
Criterion B) Carburetors:
The part numbers and serial numbers of the carburetors:
Engine type Serial number
912 A from S/N 4411057 up to S/N 4411621 inclusive
912 F from S/N 4413045 up to S/N 4413165 inclusive
912 S from S/N 4924905 up to S/N 4925000 inclusive
from S/N 9139001 up to S/N 9139252 inclusive
from S/N 9563601 up to S/N 9565000 inclusive
914 F from S/N 4421422 up to S/N 4422113 inclusive
from S/N 4422115 up to S/N 4422124 inclusive
Carburetors Carburetors
part no. Serial number
912 A/F 1/3 part no. 892500
2/4 part no. 892505
from S/N 144628 up to S/N 190938 inclusive
from S/N 144589 up to S/N 190858 inclusive
912 S 1/3 part no. 892530
2/4 part no. 892535
from S/N 145021 up to S/N 191489 inclusive /
from S/N 191491 up to S/N 191496 inclusive /
from S/N 191498 up to S/N 191499 inclusive /
from S/N 191502 up to S/N 191513 inclusive / SN 191515 /
S/N 191517
from S/N 144903 up to S/N 191601 inclusive /
from S/N 191603 up to S/N 191617 inclusive /
from S/N 191631 up to S/N 191637 inclusive /

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SB-912-073 / SB-914-055
SERVICE BULLETIN
NOTE: Carburetors with S/N higher than the range listed above, have already been inspected
during serial production and are equipped with the carburetor circlip part no. 945786.
Criterion C) Spare parts:
Further all engines are affected which have been equipped with carburetors with part number and
serial number listedwithin Criterion B) above during engine repair, maintenance or general over-
haul or any other exchange action.
Further all engines are affected which have been equipped since January 01st 2015 with circlip
part no. 945785 asaspare part orprovided within aservice kit carburetor, maintenance kit
carburetor and overhaul kits during engine repair, maintenance or general overhaul or any other
exchange action.
1.2) Concurrent ASB/SB/SI and SL
None.
1.3) Reason
Due to deviations in the manufacturing process a partial fracture of the circlip may occur. This
fracture might lead to a crack/ total fracture of the circlip which in consequence may lead to a mal-
function of the carburetor. Possible effects might be rough engine running or an unusual engine
operating behavior.
1.4) Subject
Replacement of circlip (carburetor) for ROTAX® engine type 912 and 914 (Series).
1.5) Compliance
- Immediately, on uninstalled engines / spare parts
- Within the next 25 hours of operation, but at the latest by July 31st 2020 the inspection and
mandatory exchange of the circlip must be conducted according to the following instructions in
Chapter 3
914 F 1/3 part no. 892520
2/4 part no. 892525
from S/N 143849 up to S/N 190436 inclusive /
from S/N 190438 up to S/N 190662 inclusive /
from S/N 190664 up to S/N 190864 inclusive /
from S/N 190866 up to S/N 190877 inclusive /
from S/N 190879 up to S/N 190885 inclusive /
from S/N 190887 up to S/N 190890 inclusive /
S/N 190897 / S/N 190903 / S/N 190906 / S/N 190908
from S/N 144003 up to S/N 185713 inclusive /
from S/N 185715 up to S/N 190359 inclusive /
from S/N 190361 up to S/N 190705 inclusive /
from S/N 190712 up to S/N 190740 inclusive /
from S/N 190742 up to S/N 190746 inclusive /
from S/N 190748 up to S/N 191408 inclusive /
from S/N 191418 up to S/N 191422 inclusive /
S/N 191424 / from S/N 191426 up to S/N 191427 inclusive /
S/N 191439 inclusive
mWARNUNG
mWARNING Non-compliance with these instructions could result in engine dam-
ages, personal injuries or death.

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SERVICE BULLETIN
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Initial Issue Page 3 of 13
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1.6) Approval
The technical content of this document is approved under the authority of DOA ref.
EASA.21J.048.
1.7) Labor time and credit
A labor credit will be provided for work performed by a technician with current and applicable iRMT
rating.
To apply for labor credit, contact your ROTAX®Authorized Distributor or their independent Ser-
vice Centers.
1.8) Mass data
Change of weight - - - none.
Moment of inertia - - - unaffected.
1.9) Electrical load data
No change.
1.10) Software modifications
No change.
1.11) References
In addition to this technical information refer to current issue of
- Illustrated Parts Catalog (IPC)
- Maintenance Manual Line (MML)
- Maintenance Manual Heavy (MMH)
NOTE: The status of the Manuals can be determined by checking the table of amendments.
The 1st column of this table shows the revision status. Compare this number to the one
listed on the ROTAX website:
www.flyrotax.com. Updates and current revisions can be downloaded for free.
1.12) Other Publications affected
None.
1.13) Interchangeability of parts
- All used parts and affected circlips part no. 945785 are unserviceable and must be scrapped
NOTE: For carburetors, service kits carburetor, maintenance kit carburetor, overhaul kit
etc. replace affected circlip partno.945785 with circlip part no.945786.
Work performed iRMT rating
required
Labor
credit
Disassembly, replacement of parts, re-
assembly, test run and logbook entry as
per Chapter 3 (per engine)
iRMT Maintenance Heavy 1.10 h

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SERVICE BULLETIN
2) Material Information
2.1) Material
Price and availability will be provided on request by ROTAX®Authorized Distributors or their inde-
pendent Service Centers.
2.2) Company support information
- Any possible support by BRP-Rotax will be provided on request by ROTAX®Authorized Dis-
tributors or their independent Service Centers
- Shipping costs, downtime costs, loss of income, telephone costs etc. or costs of conversion to
other engine versions or additional work, as for instance simultaneous engine overhauls are
not covered in this scope and will not be borne or reimbursed by ROTAX®
2.3) Material requirement and credit per engine
Parts requirement:
2.4) Material requirement and credit per spare part
None.
2.5) Rework of parts
None.
2.6) Special tooling/lubricants- /adhesives- /sealing compounds
Price and availability will be supplied on request by ROTAX®Authorized Distributors or their inde-
pendent Service Centers:
Fig.no. Part
number
Qty/
engine Description Old p/n Application
5 945786 2 Circlip 945785 Carburetor jet needle
5 950430 2 O-ring - Carburetor jet needle
9 230150 4 Gasket ring 10x14 - For Engine Type 914 only:
Fuel hose assy.
Description Qty/engine Part no. Application
LOCTITE 243 BLUE as required 897651 Fixation screw
mWARNUNG
NOTICE
If using these special tools observe the manufacturers specifica-
tions.

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27 July 2019 73-00-00
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3) Accomplishment/Instructions
-ROTAX
®reserves the right to make any amendments to existing documents, which might
become necessary due to this standardization, at the time of next revision or issue.
NOTE: Before maintenance, review the entire documentation to make sure you have a com-
plete understanding of the procedure and requirements.
Accomplish-
ment
All measures must be implemented and confirmed by at least one of the following persons or
organizations:
-ROTAX
®- Airworthiness representatives
-ROTAX
®- Authorized Distributors or their independent Service Centers
- Persons approved by the respective Aviation Authorities
- Persons with approved qualifications for the corresponding engine types. Only authorized per-
sons (iRMT, Level Heavy Maintenance) are entitled to carry out this work
- Persons with type-specific training
NOTE: Indicates supplementary information which may be needed to fully complete or under-
stand an instruction.
3.1) General
All work has to be performed in accordance with the relevant Maintenance Manuals
(Line/Heavy).
Step Procedure
1 Check the criteria given on page 1, section 1.1, if the aircraft engine is affected by this SB.
2 Check the engine logbook and maintenance documentation, if this SB has already been
accomplished.

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3.2) Instructions
3.2.1) Disassembly
To replace the circlip and O-ring, the following steps are necessary:
See Fig. 1.
Fig. 1 010217
See Fig. 3.
Fig. 2 AE_912_0216
Engine type 914 Series
Step Procedure
1 Unclamp the return spring (1).
Step Procedure
2 For engine type 914 Series only:
Remove the 2 fuel lines (2) to the fuel pressure regulator by removing banjo bolts M10
(3) and sealing rings 10x14 (4) on both sides. Remove cable clamp (5), release lock
nut M5 (6) and take off the fuel lines.
1
1 Return spring
2 Fuel lines
3 Banjo bolts
4 Sealing ring
5 Cable clamp
6 Lock nut M5
24
3
5
6

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See Fig. 3
Fig. 3
See Fig. 4.
Step Procedure
3 Remove countersunk screw M5x12 (7) and oval head screw M5x20 (8) with distance
sleeve (9).
Step Procedure
4 Lift chamber top (11) from carburetor. Remove throttle valve spring (12) and pull car-
buretor piston assy. (13) from carburetor.
mWARNUNG
NOTICE
Fixation screw is held in place with LOCTITE 243. Make sure to use
proper size of screw driver to not damage the aluminum fixation
screw! Heat may be applied to the piston to aid removal.
Step Procedure
5 Remove fixation screw (14) from piston.
7
8
7 Countersunk screw M5x12
8 Oval head screw M5x20
9 Distance sleeve
10 Return spring
9
10

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Fig. 4
AE_912_0210
See Fig. 5.
Fig. 5
AE_912_0211
Step Procedure
6 Remove jet needle (15) with circlip and O-ring from piston assy. (13).
7 Remove original O-ring (17) and circlip (16) from the jet needle (15) and discard.
NOTE: Take note of the circlip’s original needle position.
12
14
11 Chamber top
12 Throttle valve spring
13 Carburetor piston assy.
14 Fixation screw
15 Jet needle
11
13
15
13
17
15
16
13 Carburetor piston assy.
15 Jet needle
16 Circlip
17 O-ring 2.5x1.5

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SERVICE BULLETIN
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3.2.2) Assembly
See Fig. 6.
Fig. 6
See Fig. 7.
Step Procedure
1 Place a new circlip part no. 945786 (1) into the same needle position. Place a new O-
ring 2.5x1 part no. 950430 (2) over the jet needle (3).
Step Procedure
2 Place the jet needle assy. (3) into the carburetor piston (4) so that the needle pro-
trudes through the piston.
3 Fix the fixation screw (5) with a small amount of LOCTITE 243 and tighten in place.
NOTE: The jet needle is held in position by the circlip and its movement is
dampened by the O-ring.
4 Place the piston assy. (4) into the carburetor body. The diaphragm’s alignment tab (6)
must be seated within the carburetor body recess (7).
2
1 Circlip
2 O-ring 2.5x1
3 Jet needle
1
3

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Fig. 7
AE_912_0214
See Fig. 8.
Step Procedure
5 Place the throttle valve spring (8) into the piston and attach the chamber top (9) with
countersunk screw M5x12 (10) and oval head screw M5x20 (11) with distance sleeve
(12).
NOTE: The piston assy. must remain aligned. Avoid rotating the chamber top
while attaching screw.
6 Mount the return spring (13) again.
7
3 Jet needle assy.
4 Carburetor piston
5 Fixation screw
6 Diaphragm
7 Carburetor body
5
3
4
6

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Fig. 8
See Fig. 9.
Step Procedure
7 For engine type 914 Series only:
Attach fuel line (14) to carburetor (fuel inlet). Support the line on the carburetor brack-
et with a cable clamp (16). The cable clamps are attached with Allen screw (17)
M5x12 and new lock nut M5 (15). The tighten lock nut M5 to 10 Nm (90 in.lb).
Attach the 2 fuel lines (14) to the fuel pressure regulator with banjo bolts M10 (18) and
new sealing rings 10x14 (19) on both sides. Tightening torque 15 Nm (133 in.lb).
See Chapter 73-00-00 of the latest Maintenance Manual Heavy for the respective
engine type.
mWARNUNG
NOTICE
When fitting fuel lines, support them adequately to avoid strain or
additional load.
10
12
13
8 Throttle valve spring
9 Chamber top
10 Oval head screw M5x12
11 Countersunk screw M5x20
12 Distance sleeve
13 Return spring
9
11
8

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Fig. 9
AE_912_0216
Engine type 914 Series
3.3) Finishing work
- Restore aircraft to original operating configuration
- Connect negative terminal of aircraft battery
3.4) Test run
Conduct test run.
15
16
14 Fuel line
15 Lock nut M5
16 Cable clamp
17 Allen screw M5x12
18 Banjo bolt M10
19 Sealing rings 10x14
14
17
18
19
See Chapter 12-20-00 of the latest Maintenance Manual Line for the respective
engine type.

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3.5) Summary
These instructions (section 3) have to be followed in accordance with the deadlines specified in
section 1.5.
The execution of the mandatory Service Bulletin must be confirmed in the logbook.
A revision bar outside of the page margin indicates a change to text or
graphic.
Translation into other languages might be performed in the course of language localization but
does not lie within ROTAX® scope of responsibility.
In any case the original text in English language and the metric units are authoritative.
3.6) Inquiries
Inquiries regarding this Service Bulletin should be sent to the ROTAX®Authorized Distributor of
your area.
A list of all ROTAX®Authorized Distributors or their independent Service Centers is provided on
www.flyrotax.com.
NOTE: The illustrations in this document show the typical construction. They may not rep-
resent full detail or the exact shape of the parts which have the same or similar
function.
Exploded views are not technical drawings and are for reference only. For specific
detail refer to the current documents of the respective engine type.