Ford Mondeo cam belt tensioner.

well l have just chenged the head gasket, and have got to the cam belt tensioner. l have the engine timed ok, have looked at a haynes book for instructions on how to set the tensioner, and for the life of me l dont see how to be certain l have it right. the older zetec were easy, even l could do them. but this??? well. l have the belt on, and it is tensioned, but l cant feel any play, and l am not able to feel resistance from the spring. l have spun the engine around a few time on the crank pulley, and it seems fine, but l dont want to chance the starter motor until i am sure. anyone got any "pointers" pardon the pun. thanks eddie