29 May 2013 Current valid documentation see: 72-30-00

Revision 2 www.FLYROTAX.com Page 1 of 7

Copyright - BRP-Powertrain GmbH & CO KG. All rights reserved.

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ASB-912-062R2

ASB-914-044R2

ALERT SERVICE BULLETIN

Checking of the cylinder head assy. (2/3) for ROTAX® Engine 

Type 912 and 914 (Series)

This ASB revises ASB-912-062/ASB-914-044 Revision 1

ATA System: 72-30-00 cylinder head

MANDATORY

Symbols used:

Please, pay attention to the following symbols throughout this document emphasizing particular information.

General note

NOTE: Information useful for better handling.

A revision bar outside of the page margin indicates a change to text or 

graphic.

To obtain satisfactory results, procedures specified in this publication must be accomplished with 

accepted methods and prevailing government regulations.

BRP-Powertrain GmbH & Co KG. cannot be responsible for the quality of work performed in 

accomplishing the requirements of this publication.

1) Planning information

1.1) Applicability

All versions of the engine type:

WARNUNG WARNING Identifies an instruction which, if not followed, may cause serious injury or even fatal injury.

CAUTION WARNUNG

Identifies an instruction which, if not followed, may cause minor or 

moderate injury.

NOTICE WARNUNG Denotes an instruction which if not followed, may severely damage 

the engine or could lead to suspension of warranty.

ENVIRONMENT NOTE

Environment note gives you tips and behaviors to environmental protection.

Engine type Serial number

912 A from S/N 4,410.965 up to S/N 4,410.976 inclusive

912 F from S/N 4,413.013 up to S/N 4,413.017 inclusive
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ASB-912-062R2

ASB-914-044R2

ALERT SERVICE BULLETIN

29 May 2013 72-30-00

Revision 2 Page 2 of 7

Copyright - BRP-Powertrain GmbH & CO KG. All rights reserved.

Additional engine S/N as per ASB-912-062/ASB-914-044 Revision 2:

In addition, also affected, all cylinder head assy. 2/3 part no. 623682 or part no. 623687 from 

31 January 2013 up to 28 May 2013 inclusive.

1.2) Concurrent ASB/SB/SI and SL

none

1.3) Reason

Due to a deviation in the manufacturing process some cylinder heads may have an oil leak in the 

intake channel in the area of the valve guide. There is a possibility of small machined through 

holes, which can increase the oil consumption which may result in an engine stoppage.

1.4) Subject

Checking of the cylinder head assy. (2/3) for ROTAX for engine type 912 and 914 (Series).

1.5) Compliance

- before next flight, check of the cylinder head assy. 2/3 part no. 623682 or part no. 623687 of an 

engine with a serial number (S/N) listed in section 1.1) in accordance with the instructions in 

section 3.

NOTE: If an inspection as per ASB-912-062R1/914-044R1 have already been carried out, no further inspection is necessary.

1.6) Approval

The technical content of this document is approved under the authority of DOA ref. 

EASA.21J.048.

1.7) Labor time

Estimated labor time:

engine installed in the aircraft - - - labor time will depend on installation and therefore no estimate 

is available from the engine manufacturer.

1.8) Mass data

change of weight - - none.

moment of inertia- - - unaffected.

912 S from S/N 4,924.468 up to S/N 4,924.491 inclusive

914 F from S/N 4,421.156 up to S/N 4,421.169 inclusive

Engine type Serial number

912 A from S/N 4,410.977 up to S/N 4,410.981 inclusive

912 F from S/N 4,413.018 up to S/N 4,413.019 inclusive

912 S from S/N 4,924.492 up to S/N 4,924.543 inclusive

914 F from S/N 4,421.170 up to S/N 4,421.177 inclusive

WARNUNG WARNING Non-compliance with these instructions could result in engine damages, personal injuries or even fatal injury.
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ASB-912-062R2

ASB-914-044R2

ALERT SERVICE BULLETIN

1.9) Electrical load data

no change

1.10) Software accomplishment summary

no change

1.11) References

In addition to this technical information refer to current issue of

- Illustrated Parts Catalog (IPC)

- Maintenance Manual (MM)

NOTE: The status of Manuals can be determined by checking the table of amendments of the Manual. The 1st column of this table is the revision status.

Compare this number to that 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 defective parts and also spare parts in stock are unservicable and must be returned F.O.B 

to ROTAX® Authorized Distributors or their Service Center.

2) Material Information

2.1) Material- cost and availability

Price, availability and any possible support will be provided on request by ROTAX® Authorized 

Distributors or their Service Center.

2.2) Company support information

- Replaced parts must be returned F.O.B to ROTAX® Authorized Distributors or their Service 

Center.

- 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 overhaul is not 

covered in this scope and will not be borne or reimbursed by ROTAX®.

2.3) Material requirement per engine

parts required if cylinder head change is necessary:

Fig. no. New part no. Qty/

engine Description Old part no. Application

- - as required spark plug12 897225 912 A, 912 F,

- - as required spark plug12 297940 912 S

- - as required spark plug12 897257 914 F

- - as required cylinder head assy. 2/3 623682 Power section 

912 A, 912 F, 

914 F

- - as required cylinder head assy. 2/3 623687 Power section 

912 S
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ASB-912-062R2

ASB-914-044R2

ALERT SERVICE BULLETIN

29 May 2013 72-30-00

Revision 2 Page 4 of 7

Copyright - BRP-Powertrain GmbH & CO KG. All rights reserved.

2.4) Material requirement per spare part

none

2.5) Rework of parts

none

2.6) Special tooling/lubricant-/adhesives-/sealing compound-Price and availability

Price and availability will be providedon request by ROTAX® Authorized Distributors or their Service Centers.

parts required if cylinder head change is necessary:

- - as required O-ring 6.4x1.8 430205 valve cover

- - as required O-ring 105x2.5 250285 valve cover

- - as required O-ring 16x5 850930 oil return tube

- - as required valve stem seal 230810 cylinder head

- - as required O-ring 43x2 230910 intake manifold

- - as required O-ring 19x2 950180 bent socket

- - as required Lock nut M8 842950 exhaust bend

- - as required Lock washer A6 945751 intake manifold

Fig. no. New part no. Qty/engine Description Old part no. Application

- as required valve spring 

loading jig assy.

877387 cylinder head

NOTICE WARNUNG When using these special tools observe the manufacturers specifications.
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ASB-912-062R2

ASB-914-044R2

ALERT SERVICE BULLETIN

3) Instructions/Accomplishment

NOTE: Before maintenance, review the entire documentation to make sure you

have a complete understanding of the procedure and requirements.

AccomplishmentAll measures must be taken and confirmed by at least one of the following persons or 

organization:

- ROTAX® - Airworthiness representative

- ROTAX® - Distributors or their Service Center

- Persons approved by the respective Aviation Authority

NOTE: All work has to be performed in accordance with the relevant Maintenance

Manual.

Safety notice

3.1) Checking of cylinder head assy. 2/3 

3.1.1) Introduction

This check has to be done in order to establish if there is evidence of excessive oil consumption. 

New or used engines have to be checked by examining for this evidence as detailed under 3.1.2) 

Checking of spark plug tip on cylinder 2 and 3.

WARNUNG WARNING Proceed with this work only in a non-smoking area and not close to sparks 

or open flames. Switch off ignition and secure engine against unintentional 

operation. Secure aircraft against unauthorized operation. Disconnect 

negative terminal of aircraft battery.

WARNUNG WARNING Risk of scalds and burns! Allow engine to cool sufficiently and use appropriate safety gear while performing work.

NOTICE WARNUNG Should removal of a locking device (e.g. lock tabs, self-locking fasteners, 

etc.) be required when undergoing disassembly/assembly, always replace 

with a new one.
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ASB-912-062R2

ASB-914-044R2

ALERT SERVICE BULLETIN

29 May 2013 72-30-00

Revision 2 Page 6 of 7

Copyright - BRP-Powertrain GmbH & CO KG. All rights reserved.

3.1.2) Checking of spark plug tip on cylinder 2 and cylinder 3

See fig.1.

NOTE: If the cylinder heads 2/3 part no. 623682 or part no. 623687 have already

been installed in the course of a repair / an overhaul, carry out an engine

test run (a minimum engine running time of 20 minutes is required). This

must be done prior to the checking of the spark plug tip. 

See current issue of Maintenance Manual (Line) of the relevant engine type.

NOTE: Unusual deposits (excessive carbon or oil) on the spark plugs are an indication of a defective cylinder head which must be replaced. Figure 1 shows

comparison between a used spark plug in normal condition and one that is

not.

3.1.3) Replacement of the affected cylinder head

If excessive deposits (oil or carbon) are found on the spark plugs the cylinder head must be 

replaced in accordance with the relevant Maintenance Manual (Heavy) and any relevant aircraft 

manufacturer instructions.

NOTE: At tightening the cylinder head with 2 collar cap nuts M8 and 2 hex. nuts

M8 pay attention to the changed tightening torque. Tighten to 10 Nm

(90 in.lb) and then in addition tighten further by applying a 120° rotation.

- Install new spark plugs.

- Restore aircraft to original operating configuration.

- Connect negative terminal of aircraft battery.

3.2) Test run

Conduct test run including ignition check and leakage test

3.3) Summary

These instructions (section 3) have to be conducted in accordance with the time scales specified 

in section 1.5. The execution of the mandatory Alert Service Bulletin must be confirmed in the logbook.

Approval of translation to best knowledge and judgement-in any case the original text in German 

language and the metric units (SI-system) are authoritative.

3.4) Enquiries

Enquiries regarding this Alert Service Bulletin should be sent to the ROTAX® authorized distributor of your area. A list of all distributors is provided on www.FLYROTAX.com.

Step Procedure

1 Visual check of both spark plugs per cylinder (top and bottom).

NOTICE WARNUNG Affected spark plugs with such deposits shown in chapter 4 Fig. 1, have to 

be removed and can not be reinstalled.
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29 May 2013 72-30-00

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ASB-912-062R2

ASB-914-044R2

ALERT SERVICE BULLETIN

4) Appendix

The following illustrations/drawings should convey additional information:

Fig. 1 09884

spark plug

NOTE: The illustrations in this document show the typical construction. They may

not represent 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.

okay

normal

not okay

oil fouled