If you are trying to trace on IoM then even land records under the best conditions will not get you back prior to c. 1500 - Most parish records start to peter out by 1650 and even after this period there are significant gaps.

Those unfamiliar with Manx names assume because a name is unusual in their context that it will be unusual on Island - wrong assumption that has led to many false genealogies. The Manx also tended to use relatively few 1st names thus all too easy to lose a generation in a sequence eg of Wm Cains.
Try www.imuseum.im for some help.