The 650GS is in general terms a little overweight, the KTM 640LC4 Adventure weighs in at 158 kgs dry and 180 kgs wet (2003 model) where the 650GS weighs in at 177 dry and 193kg wet. The 650GS feels top heavy, and it is.
There are however simple things which can be done to take some weight out of the 650GS dependant on how pedantic and obsessive you wish to become.
But first let us consider a few basics
All weight counts. It may seem to be only a little bit here and a little bit there but all those little bits add up
Not all weight is equal. There is a big difference between taking out a few grams on a component down low on the machine and the same few grams out of a component mounted up on the top of the machine.
Weight reduction comes at a price, both economic and in terms of strength. To quote from a hardened race engineer, not all weight is worth saving when you look at the economic cost. A pack of titanium bolts for instance seems like a simple and effective solution but when you calculate the price per gram of weight savings the picture looks very different and in most cases not economically viable.
Anyway despite the words above, like any pedantic owner who is every workshop's nightmare I have cleaned and weighed each component as I have needed to work on the machine to see where some weight can be removed
A weight saving in excess of 10 kgs is possible. A list of the weight savings which can be achieved is below.
The above list only covers components which do not change the overall design of the machine there are considerable weight savings which could be achieved with fairing and rear compartment replacement dependant on how adventurous you want to be.