6718 throttle return spring location

[dandd]

Can anyone tell me where the throttle return spring is meant to locate.?
At the moment its tied of to the power steering hose with a bit of wire.
Also is the engine in a 6718 a UR1 series? Are there any manuals available?
Thanks
Dan

 

[palof]

Engine in 6718 is UR1, engine marking "6701"
Spring is located on shaft connecting foot throttle with "hand" throttle. Shaft is located on steering case. But usually is spring broken and someone use spring between fuel pump lever and "glass" fuel prefilter holder.