Got Topspin and Twintwist today, complete and in very nice shape. Verily, I actually had a Topspin a long time ago and I don't remember this little lever on the back of his head, Twintwist's too. It's a flat lever that rocks side to side a little bit. Doesn't seem to do anything. Thoughts?

 

Must be my maturity talking, because these little guys are super cool! *boing!* My son's gonna love 'em.

They are super cool. I got them last year and I was surprised at how nice they looked. G1 was the best, even when it came to gimmicks like the Jumpstarters. The stuff they make for the younger kids in the movie toy lines have got nothing on the G1 gimmick Transformers.

IIRC it was a removed function, since Jumpstarters are from Diaclone. I believe it was something to do with balancing... let me go see if I can look it up.

 

I tried here, but nothing specific about the feature. This site you might like anyways:

http://diaclone.net/orid/diabaku/index.html

 

Anyways, TFWiki says its just there for physics reasons...

http://tfwiki.net/wiki/Jumpstarter#Generation_1

Topspin was my very first Transformer.

The slider on the backs of their heads was to alter their course (curving vs straight) as they shot forward on their motors.