BMW 318is Coupé, Honda VFR 400 NC24, Honda magna 700
niks - this is the older w124 which uses an electromagnetic clutch to engage and disengage the clutch instead of the viscous thingy you have, sounds kinda funky tho XD
i wouldnt try stopping the fan with this clutch disengaged and the fan spinning, i'd lose a finger!
The other fans widely used are the viscouse type .
the standard test for those is to run the engine up to 80C and see if the fan blades will slice a carrot,, if the fan stops the it needs a new visco coupling,, some folk re fill them.
Vsco fans cut in at 80C and electric at 100C that is for all cars