RE: "newbie" prop question
Gotcha - the general sentiment about standard plug tapped Cox heads is that they are certainly a way to get the engine running again and with respectable results, but they usually result in something like a 1000-1500 rpm loss, although I don't know if that is a safe blanket statement or not. And with the ready availability of the Nelson conversion head, which uses much more reasonably priced plugs that work great, and costs little more than a new Cox head will fetch - these days it should almost be a standard. Plus the more we use them the more likely they are to remain available for a long time too.. this is worth thinking about, 1/2A fans. You know how manufacturers can come and go, much as we hate to see that ever happen. Even manufacturers with such amazing histories as Cox.
I think you have one of two problems:
1. Crud in the fuel system. I'd say the less you have disassembled the motor, the less the chance that you have/had a leak at that o-ring, and the more likely you have crud in the fuel system somewhere or another similar fuel impediment:
- make sure the fuel pickup tube is attached, in good shape (it's likely stiff as a board but if it is sound then you can live with it) and oriented to the bottom of the tank.
- the nipple to which the fuel pickup attaches is a classic hiding spot for a wad of gunk. As a matter of fact, this very afternoon I cleaned up an old but little used Golden Bee for a buddy (I do NOT want to give it back). I thought I had cleaned and checked everything, but lo and behold it would not draw fuel, first hardly at all and then none. So I stripped it again, and that's where I found the reclusive booger. I blew it out with contact cleaner and the engine started and ran on the second flip with the needle out 3-1/2 turns.
- this has nothing to do with current problems, but does that fuel now have at least 20% total oil? 22-23 maybe..?
2. But yeah, you could really have a leak there if you are having problems making the seal work.
3. Beyond those, maybe check over the reed valve - is it there, does it seat and pass the suck-blow (gently) test, acting as a one-way valve?
Hope there is something there helpful to you. That's what I'd be fooling with anyways.
Always remember: Clean Cox are happy Cox! [X(]
MJD