ORIGINAL: Lou Crane

On just a quick rip over the thread, I didn't see a comment that may be needed:

Make sure whether this is an ABC or iron in steel piston/sleeve engine: a small magnet will pull to the iron&steel... I doubt it is ABC, because of when it was likely made. If iron-steel, it will benefit from a fuel with significant castor oil content, particularly in early running. Messy, yes, but very suitable for iron-steel... After it loosens up and starts to feel right, it may be happy on a fuel with 22%-25% oil, at least half of which is castor.

And, yes, Fox did make a single BB schnuerle 40 in the late 70's/early 80's - this appears to be one of those. As mentioned, it will probably be happier unloaded on a light prop load. Not as likely to prosper at low RPM/high load on a large diameter prop... Notice in the front view of the case?- the front end of the shaft runs in the aluminum case; no bronze or other bearing shell. That can cause a bit of dark oil weepage, from wear on the aluminum. Shouldn't be of serious concern, just another juicy aspect of a plain aluminum bearing out front.

OBTW, all the case screws are 4-40, except possibly the carb and muffler mount screws. It looks like the repaired backplate mount bolt boss you repaired was the one on the case, just above the mount lugs, on the side away from the exhaust? Neat job! The stock Fox muffler is not very quiet, if noise is a problem in your area.

Enjoy!