Posted by Gmondun on 10/03/11 - 1:31 PM
#1
Hi,
I'm looking to replace the gear oil on my mercury outboard. I know I need to unscrew the small screw first and then slowly unscrew the vent. Any idea what type of screw is in the small hole? I can't see anything when I put my flat head screw driver in there. I'm also not sure if it's a screw that comes completely out or just needs to be turned a quarter turn.
Thanks,
Gordon
Posted by msd58 on 10/03/11 - 3:56 PM
#2
Gmondun wrote:
Hi,
I'm looking to replace the gear oil on my mercury outboard. I know I need to unscrew the small screw first and then slowly unscrew the vent. Any idea what type of screw is in the small hole? I can't see anything when I put my flat head screw driver in there. I'm also not sure if it's a screw that comes completely out or just needs to be turned a quarter turn.
Thanks,
Gordon
Here ya go:
http://www.youtube.com/watch?v=Wj0la6...j0la6c5FDg
http://www.youtube.com/watch?v=JgX1Q6...re=related
Edited by msd58 on 10/03/11 - 3:57 PM
Posted by Finnegan on 10/04/11 - 1:09 PM
#3
Both the drain and fill screws on your 90 horse Merc "Tower" are the same. One is not smaller. You need a LARGE blade screw driver to remove them so you get the leverage you need and don't tear them up.
First, trim engine just a little out (up) from vertical. Completely remove the bottom plug first, while holding a drain cup underneath. It will have a magnetic shaft on it to attact gear remnants. This is normal if not excessive. Then remove the top vent plug competely. It does not have the magnet. Oil will then pour out the bottom hole. Allow to drain for a few minutes.
To fill, screw in the pump bottle hose, and pump in the oil until it comes out the top hole. Then re-install the vent plug. Next quickly remove the filler hose and install the bottom plug, after first removing any metal filings from the magnet.
Now you're good for another 100 hours.