I have had a LionChief Polar Express Set since the year it was introduced. The engine has always smoked like a champ. This year I didn't have it running under the tree (new location, forgot to build a new platform), so I kept it in reserve at The Grange and ran it on our Christmas Layout when my kids or others were around that would have liked to operate something with a remote. Yesterday we had an engine overheat so I quickly swapped it out for the PE. I loaded it up with fluid and it was running great for about 15 minutes. Then I noticed that the smoke output had completely stopped. I could see the smoke pooling up at the top of the stack, so I didn't figure on the element going bad. Took it home last night, tore it down, and cleaned it out. Upon reassembly I noticed the plunger was getting stuck in the "UP" position, which ID'd why the production stopped (though I have no idea why since it had been running great for 3+ years). I found this video that pointed to an easy fix:
My problem now is that I can't seem to locate a viable replacement spring. I went to my local Big Box who pointed me towards a local Ace/True-Value. I went to True-Value this morning and they only had larger, more powerful springs. I did walk out with some graphite, which I applied with a brush to the plunger and the interior of the receiver on the unit. That unfortunately hasn't worked since it still gets stuck "UP" when depressed.
Any ideas as to resources for the type of spring mentioned in this video?