The weather was very nice today so I had a run with my ASTER Southern Railway Mikado 4501:
The fiberglass wicks that they come with. Happened today after refilling was unable to get them to relight until I remove them and put them back in Really strange. Also that is one smooth running engine you got there!I have never had that problem.
What wick material are you using.
Have you checked that the sump is still full when your wicks go out?
David Leech, Delta, Canada