Vendo 39 timing woes

I'm reading the instructions on how to time the machine, but it seems like something is off (could be me but I'm not sure).
(Turn bottle drum counter clockwise till #39 is in the little window. Then set locks.) What pulls the bottle drum to make a complete circle?  I have one weight on the bottle drum at the back of the #9 bottle slot.  How does the bottle drum rotate without being balanced? Just bought the machine and I'm unsure how it vends.
Can anyone give me an idea??

[Jim]

Hello Anthony,

Is this machine restored and has the drum been replated?
Does your drum have recessed numbers for each bottle opening?

It seems you are attempting to utilize the dial in the center of the drum to set things up...

Let's say the drum has never been taken apart, because if it was and wasn't reassembled properly, you'll have propblems like you are now; but let us assume it wasn't disassembled...
With the drum set at 39, the counter-weight should be horizontally to the right of the center mounting post. At this point if no bottles are loaded, it will only vend until the counter-weight gets to the bottom because there's no bottle weight to continue rotating.
My recommendation is to fill the drum with soda and then set the little windo to 39 and see how vends
Lastly, are you reading the decal on the door liner, Vendo 39 Loading Instructions, or do you have the manual? In either case, here's a little more info...