The BMAA has recently received reports that some replacement Floats (fitted to comply with Rotax Bulletin SB-912-067 UL) have also been sinking, in some cases after minimal hours of operation. It is therefore highly recommended to undertake regular checks as per the Rotax Bulletin SB-912-065 R3, which states the floats should be inspected every 25hrs. It is also recommend to consider inspecting the floats, before any flight when the engine has not been run in the preceding 30 days, or more. If you experience any rough running it is highly recommended that an inspection of the floats is undertaken immediately.
See the BMAA Inspector Notice for more details.