How do i change the oil on my lower unit?

[badger]

I drained out the oil on my lower unit and filled w/80w-90 marine that i got from the guy i bought my boat from about a month ago is their another kind of lube that i need to fill or mix with it? any info on on how change oil or maintain my outboard motor will be appreciated, it a 1966 mercury 650 outbord thanks.

[187fish]

Well, I'll give you a few tips that have been working for me and anyone can add to it. I also have an older outboard, but it was neglected by the previous owner. The lower unit oil is done about once a year. Lower unit oil drains out of a plug on the lower part of the lower unit. To add oil to the lower unit, remove the vent screw at the top of the lower unit and pump oil in from the bottom till you see it coming out of the vent hole. Quickly screw in the drain plug and then the vent screw. About every 3 or 4 trips on the boat, I check the torque on head bolts and other important bolts, check electrical connections, check fuel and oil lines for leaks, once or twice a year replace impellar. Here is great website that has tons of boat and engine info, http://forums.iboats.com/ Hope that helps you some. 187

[XFACTOR]

Well, I'll give you a few tips that have been working for me and anyone can add to it. I also have an older outboard, but it was neglected by the previous owner. The lower unit oil is done about once a year. Lower unit oil drains out of a plug on the lower part of the lower unit. To add oil to the lower unit, remove the vent screw at the top of the lower unit and pump oil in from the bottom till you see it coming out of the vent hole. Quickly screw in the drain plug and then the vent screw. About every 3 or 4 trips on the boat, I check the torque on head bolts and other important bolts, check electrical connections, check fuel and oil lines for leaks, once or twice a year replace impellar. Here is great website that has tons of boat and engine info, http://forums.iboats.com/ Hope that helps you some. 187

After filling you install the vent screw tight with a new gasket first. Then you remove the 90W pump or tube from the fill hole and quickly install the lower plug with a new gasket. If all the seals in the lower unit are good the vent plug sealed first creates a vacuum and keeps the 90W from just pouring out the fill hole.

[POSTAL]

everybody gave good info ,but if you want a superior lube and wear protection and the best water resistant oil .put in royal purple max gear diff oil full synth .Thats all I use in all my motors and jet ski pumps and customers boats also .any major auto parts store will sell it

[play4therush]

you need a pump device to fill the oil from the bottom up.