I've got a fussy lantern and since I'm in the states you all may have more experience with this particular model. I do a TON of repair and restoration and this lantern has given me a fit. Now starting out, the mantle is too big because I really like the midstate lamp company lightouse 525 500CP monster mantle. It does have thorium and my 237s, 214, and a couple 200a's do amazing with this mantle. I don't know if my 249 has it for sure but I think it does as well. The issue is it just does not run well, requires pumping, and is generally fussy. It also likes preheating so much it will fill it's own cup when running, and lights it. It has not done this the last few days since I run it daily, I do have a new gen for it coming in the mail though that will be a long while probably. So is the large mantle the issue? I'd hate to knock it off. I've flushed it a few times and cleaned out the burner with no luck. I'll try another cap on it from a 335 (should have done sooner). Thanks!