There's a spring loaded brass bar by the injectors. When the bike's cold the bar is fully to the right (i.e. in the cold start position). After the engine is started and the temperature begins to rise, a wax element inside the coldstart mechanism expands and gradually moves the brass bar across to the left. If you give it a push here (see RHS view) while the engine is running the revs should drop as it moves in. Its full movement when cold should be around 20mm.
The brass bar can seize in its mount, the effect being that starting from cold in the winter may be difficult. All you need to do is spray with WD40 or light oil after cleaning to keep it mobile. (Grease may be too heavy to allow it to operate freely?) If yours has seized (like mine was) spray the area with penetrating oil and push - or in my case give it a gentle tap from the left hand side (see LHS view) with a piece of wood propelled by a hammer. If its moving OK and the cold start still does not operate I have heard that the wax element can fail - but that's another story.
RHS view
LHS View
