Space Bug, Space Bug Jr. and Stepped cylinder Babe Bee weights.

With its long nose and large tank I would have expected the Space Bug to weigh more than the slim BB

I am totally surprised that the Babe Bee weighs more than the clunky Space Bug.  

8:17 pm and dark.  Just got through mowing two and a half acres.  My mower has headlights, helpful when finding my way into the garage.

Edit add:

We had the same thought Andras and at the same time.  

I think it may be the aluminum backplate of the Space Bug being lighter than the Zamac metal back of the Babe Bee that may help to answer why the Space Bug was a touch lighter, just a gut level feeling. But, the Zamac back might have been a touch easier to produce, which would lower the cost of the Babe Bee, to the extent reducing its price to basically causing Cox to become the dominant engine in later years.

Leroy Cox was a genius with his revolutionary use of screw machines to produce the Bee engines, outdoing the cast engines of other manufacturers. But his earlier cast engines were also well done, helping Cox to become a domineering force in later years. Even my cast crankcase R/C Bee engine of the late 1970's was a very good runner, ultra reliable.

It was definitely the extruded aluminum cases (made for Cox by Alcoa) that helped with cost, that and their Temp-Trol machining process that produced close tolerances that almost every engine ran great, unlike others that wore out after 4-5 flights.

Wonder what the spring starter weighed? The Babe Bee case and larger crank is kinda heavy compared to SB, SBJ