Mandatory Service Bulletin: Inspection and/or replacement of expansion tank assy. for ROTAX® 912, 914, 912 i, 915 i and 916 i (Series) Aircraft Engines

Im just trying to understand so please excuse my ignorance. The SB says  my engine was delivered  with expansion tank part# 922666 or 922668. I have a new never flown engine so I would assume I have one of those part # tanks as my SN falls in the range of effected engines. Looking at my tank, the sticker on the side says 622051. That part number does not come up in the IPC. If I were to order a part would I order 622051 or 922668?

Because I dont have 922668 does that mean someone has worked on my engine? Its new so thats why I am confused.

Hi Eric,

There are multiple types of expansion tanks with different part numbers (P/N). P/N 622051 is for a different style of expansion tank (see attached) and is NOT subject to this Service Bulletin (SB).

It appears that your engine was ordered with a different type of tank to meet your aircraft's installation requirements.

Only P/N 922666 or 922668 (4-port tanks) are affected by this SB.

That said, if you’re not satisfied, you always have the option to perform an inspection to verify that the welds are complete and uniform.

It seems that I got lucky. Intending to replace my ~2005 OEM tank (thin pipe walls, no inspection glass) at the next rubber change, I ordered a replacement from LEAF 2-3 years ago, presently sitting on a basement shelf. While it came in a bag labeled 922666, the tank is marked "VE 22536-0, 622050, 174/07/2022". But poking around with a borescope, it seems that a couple internal pipes are quite badly aligned with the wall openings. Should I fret about this, or is it normal?