Leaking Sight Glass (Video Link)

Roger, have you actually used the sight glass for anything?  Can you think of a real use for it?  It just seems like an extra potential leak source to me.

I would say that if your coolant is low enough that you can see its level in that glass, you have already had a problem for a while.

No I never use it because I can't see into very well. I just take the cap off and look if I need to. I do not pull the cap off on every pre-flight or you'll wear it out.

The sight glass is visible in all the Rotax Pubs "Coolant system" sections that I have downloaded. But it is only identified and labeled in the Line MM: 

12–20–00

Page 27

September 01/2018

I got my engine in 2018... no sightglass, thankfully.