Me and my buddie were changing the lower unit oil in his 1980 mercruiser 470 alpha one? We pumped in 1 qt. and none came out of the top hole. My question is should we get more oil and keep going till oil comes out or is 1 qt. enough? we were told 1 qt. is the proper amount but dont want to fry the lower unit either.

Keep putting it in until it comes out the top. Chances are, it won't take much more.

It is only full after it starts to come out the top hole. Get another qt. and fill till it comes out!!!!!!!!!!!!!!

Thanks for your help. We'll fill till it overflows.:D