Originally posted by markus1971
Hey guys!! We are getting off the subject here aren't we? This post was about the engine pictured above. I need to know about it, not OS engines... can we get back on the subject please?? Thanks !! 
You have a 70's vintage Fox bushing bearing 40 with an antiquated butterfly carb. I had the exact same engine, but with the newer carb, back in about '83. It was an OK engine, hauled my many times rebuilt Epoxy Stick around until I sold it to get a more modern engine.
There was nothing spectacular about it, it served me long enough to learn to fly, and long enough to realize that there were much better engines than a bushing Fox 40.
I would place a value on it of about $25~$35, maybe $5 more if it had a muffler.
I think it would make a much better conversation piece than a flyer, if you decide to run it be sure to run fuel with castor oil only as the lube due to the piston/bushing material used. 22~24% castor, 10% nitro ought to be just dandy.
Hope you enjoy your vintage Fox engine.