912 uls oil filter won't come out

They can be very tight. The best tool is the ring spanner designed to fit that size filter. See this one:

https://ecclestonaviation.co.uk/product/oil-filter-spanner/?v=79cba1185463

I have also had success with these:

https://www.misterworker.com/en/expert/adjustable-oil-filter-wrench-hgv-e02f12f5/10247.html

Don't bother with strap wrenches, the adjustable 3-jaw ones or the end cap style ones, they all just slip if the filter is really tight.

Thanks a lot Kevin!!

If the filter has been put on according to recommended practise, almost any filter tool will remove it.

On the other hand if some brut has tightened it beyond normal torque, you could try using a HD hose clamp, round the barrel of the filter, as tight as you can get it. Then using a flat blade screwdriver or drift and hammer, carefully tap it in the anti clockwise direction.- always worked for me.

Oil filter wrench is available from Lockwood and other ROTAX dealers and Service Centers in the US. 

TLFW3 Oil Filter Wrench

See attached photo...

Thanks a lot Sean!

Let's see which method works.

Regards,

Barak