THIS IS A NEW REVISION Updating the ASB previously released December 6th, 2018.
Rotax has now established a specific engine S/N range for this ASB.

All engines that are within the below S/N range are affected and must comply with this MANDATORY ASB Immediately. Further engines affected were equipped with the sodium filled 32mm exhaust valves P/N 854113 with a production lot number 0317 and 0517 during an upgrade, repair, maintenance or general overhaul and must comply with this MANDATORY ASB immediately. Essentially, all sodium filled 32 mm valves with P/N 854113 with a production lot number 0317 and 0517 are affected by this ASB.

915 iSc A from S/N 9127301 up to S/N 9127316 inclusive
915 iSc B from S/N 9122510 up to S/N 9122523 inclusive
914 F from S/N 4421923 up to S/N 4421964 inclusive
915 iS A from S/N 9132001 up to S/N 9132182 inclusive
914 UL from S/N 9576603 up to S/N 9576724 inclusive

If your engine is affected you must:

• Follow the specific instructions laid out within the ASB.
• Contact your local Rotax distributor, dealer, service center or repair station and provide them with a copy of the ASB if they don’t already have it.
• Have the sodium filled valves P/N 854113 exchanged for non-affected exhaust valves prior to flight.

NOTE:
Only affected 914 (Series) engines may optionally elect to replace the affected valves with Solid exhaust valves P/N 854111.
All affected 915 (series) engines must replace affected valves with new sodium exhaust valves as specified in the bulletin.

ROTAX has released a new Tech Tips video
on the subject of this Alert Service Bulletin.
(CLICK HERE TO VIEW)

The affected Sodium filled exhaust valves (part no. 854113) are marked with an indent (1.5 mm (0.04 in.) radius) in the center of the valve crown, as shown here: