From Boaty I bought a Wilesco D52 marine engine and set it up statically for a test run.
I followed all instructions but when it started up it ran for about 30 seconds at a reasonable speed which was okay for the size of boat I had in mind.

After the 30 seconds it slowed down considerably and it appeared that the way the burner was designed it was struggling through lack of air thus it did not have sufficient heat to maintain steam pressure.

I took the burner out and also removed the mounting bracket for the burner. I drilled extra air holes in both and also some corresponding holes in burner tray and base of the holder. I chopped the fuel tablets into smaller portions and when the boiler was fully fired up the performance of the engine increased slightly and it was more consistent over a longer time period.

In relation to the physical size of the engine and boiler, it appears to under perform .

Has anyone else had same problems with this model of engine and if so how did they overcome them.

Boaty