I have a Black Widow that has never been able to make a consistant run.  On the bench, you have to fiddle with the needle to keep it smooth, and in the air it is impossible.  What am I missing here?  Russell

Thanks for you ideas, Alan.  That engine has never really run right.  There were burrs on the back of the crankcase around the screw holes, when I looked for possible leaking areas they were quite apparent.  I lapped the case back on a piece of fine sandpaper, changed the gasket (I actually had a brand new one!), and it ran out a tank better than ever. Amazing what a difference a smooth mating surface can make.  I'll give it a flight trial if the wind ever stops blowing.  Russell