Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Bonjour Tony,
Your siren has been made by Microcosm, I have two of them. I also have difficulties to make them play, especially at the beginning because I think that residues in the steam block the little moving part. In this case, WD540 is my friend.

Furthermore, they seem to need more than 40 PSI to start operating correctly and I settle my gas regulators to 30 PSI 


Other test at about 60 PSI on a larger boiler:


When it is hot, it is better and on the bench, everything was almost correct:


As you can see/hear it, a lot of steam is needed to make them sing