I know this is not much help but the same thing happened to me it took me ages to figure out and it was very time consuming and fiddley it will become clear how it fits together, remember it can only fit one way.
It you take off the main case you can see where the throttle cable goes, you have got a choice of holes to fit it into use a set of long nose pliers to put the cable back into one of the retaining holes, pick a hole that makes the cable taught.
The problem with taking the main case of is that it is held on with anti tamper proof screws which are a star shape.
Sorry i cannot be any more help with the assembly it is difficult to expain in words how it all fits.
Garry McGlennon, November 2007