ORIGINAL: Sandore
of guys I work with suggested the tank O ring on the BW. I tried shaving off a very thin piece of fuel tubing to replace the O ring, but that didn't work. Case gasket appears to be ok. I did find a link to some detailed instructions on how to rework a Cox engine
Does it leak fuel out of the tank when filled?
Or does it not leak, and does not draw fuel? (key symptom being that it happily runs out a prime then stops, starving for more fuel).
Or you said not running right - does it run, but something is amiss? If so, what does it do?
What fuel and prop did you use?
Those little cut o-rings can take a couple of tries to get right. Too thick and they mush so badly they are a wreck. Too thin and they don't work. Too crooked and they don't work.
That plug conversion of yours could be a major factor too. What plug is in there? Does it seal perfectly and all that? I think you already know the general sentiment about standard plug conversions of Coxes by your "don't laugh" comment.. Many have done it, but the performance always seems to suffer in some way, and at best I think some efforts run at par.
MJD