im getting ready to put my lower unit back together on my 1986 mariner magnum 150. I have ordered the special tool. what I need to know is how many foot pounds the bearing carrier retainer nut (castle nut), needs to be torqued down to. Ive been told its very important to get it the right torque. thanks very much.

210 ft lbs apply special lube 101 or 24C with teflon to the threads

You may need to use a special chart to calculate the exact torque because the length of your torque wrench can affect the actual torque on the nut it -self.

thanks for the info, do u recommend a new castle nut?

bearing carrier retainer nut is inexpensive 13-20 dollars tops I think. I would not install the old one.