Try our new info resource - "Aladdin's Cave" (Main menu)Just added a separate link to Ash's Dropbox thread (shortcut)
It needs to be tapped in to place. Obviously not too hard, but firmly.
You did fit it with the pin facing outwards? and the generator cover needs to be fitted to hold it in.
"Wet" alternator only on 750, smaller ones are dry and have a seal behind the rotor