Golden Bee

I'm not 100% certain of the chronological date changes that have occurred for these engines. I just generally associate the black drive washer as Bob mentions as being the early examples. The large knob needle valve which I prefer is also a indicator. That being said, I would think the thin wall cylinder is also a trademark of the earliest examples. What I've discovered with my collection. I'm thinking I have at least 10 of them is that the 70's examples had the thicker wall nose on the case whereas the early examples utilized the swooping narrow nose.

In addition to the the eye catching changes were the internal changes. Some of my later examples came with dual bypass porting similar to the Black Widow where the earlier versions used single ported Babe Bee cylinders. I know Roddie also posted the internal venturi differences. I've noted that myself as I have just the tanks and visibly the inlet openings are significant in size.