I have this split pea lighter from CountyComm/Maratac:
http://www.countycomm.com/splitpea.htmlIt always dries up after about 
two months of storage.  I've tried changing the O-ring, applying grease to the O-ring, applying no-grease to the O-ring, tightening really tight, tightening not so tight.  Nothing works.  It still dries.  Thus, it's not carry worthy.
Possible solution...I installed this O-ring:
http://www.oringsusa.com/catalog/product...it26noks59osvg3That O-ring is a lot more robust than the O-ring that comes with the Maratac lighters.  After a few months, I'll report back to see if this O-ring holds the fuel in there.  HOWEVER, it is important to note that although this O-ring fits well on the Maratac lighters, it does NOT fit on the cheaper knock-off from DX.com:
http://dx.com/p/super-mini-vintage-oil-lighter-3734By the way, I put fuel in my cheaper peanut lighters from DX.com about 
3 years ago, put them in storage, and forgot about them.  All five of them still have the fuel in there and still light up like new.  Go figure.