Rotax has issued an urgent and mandatory service bulletin on their 912/914 series engines. It applies to a limited selection of engines built between June 2016 and October 2017 – check your Foxbat/Vixxen 912ULS engine number against the list below to see if you are affected.
(A) from S/N 6 785 971 up to S/N 6 786 198 inclusive
(B) from S/N 6 786 501 up to S/N 6 787 000 inclusive
(C) from S/N 9 569 001 up to S/N 9 569 690 inclusive
(D) from S/N 9 569 693 up to S/N 9 569 702 inclusive
PLUS S/N 9 569 823
Rotax reports that deviations in the manufacturing process of the valve push-rod assembly may cause partial wear on the rocker arm ball socket. This wear could lead to a rocker arm cracking/fracture which in consequence may lead to a malfunction of the valve train. Possible effects are rough engine running or an unusual engine operating behaviour.
The bulletin requires the removal of the rocker covers of affected engines and an inspection – and if needed, replacement – of the valve pushrods.
In simple terms, if the pushrod ends are a silver-ish colour, they are OK. If they are black they will need to be replaced.
Time frame for completion of the bulletin is:
– either at the next scheduled service
– or if a scheduled service is not due, within the next 25 hours of engine running time
– or if 25 hours running time is not completed, by 30 April 2018 at the latest
Here are links to the Bulletins:
What needs to be done: https://legacy.rotaxowner.com/si_tb_info/serviceb/sb-912-070.pdf
Which engines are affected: https://legacy.rotaxowner.com/si_tb_info/serviceb/sb-912-070ul.pdf
If you believe your engine is affected, please contact Bert Flood Imports, the Australia Rotax engine agent, for more information.
Bert Flood Imports phone number is: 03 9735 5655