Logo
FULL SITE MENU

1969 25 hp Evinrude Lower Gear Unit leaking oil

W

Wayne Brasel

New member
icon1.png
Lower Gear Unit

I was cleaning my boat yesterday when I noticed the lower unit was leaking gear oil. It did appear that water had entered into the gear unit but I was wondering if someone could tell me what goes in this hole that is now there. I reviewed my manual and didn't noticed anything and was considering that it was maybe some sort of cap that may have vibrated out. Can I seal this with epoxy? I understand that I must clean it out really good to make sure it doesn't rust. That is a given but I need to find a way to seal this up. Not sure if a screw was there before and had vibrated out. I would appreciate anyone's advice on what is the best resolution.

1969 25hp Evinrude (25902B) 2-stroke

The hole I am referring to is the one in the middle near the prop.​
 
Well , all I can say is that is the oil drain screw that is missing.-----------------If it has been run like that you need to take the lower unit apart for inspection.------------It would have been running with water in there instead of oil !!!
 
I removed the fill/drain screws to drain out all of the oil. I am referring to the screw that is in the middle near the propeller that is between the fill/drain holes. I just want to make certain that I can just find any screw and or plug for that hole. Again, I was in the process of draining the oil out and cleaning the lower unit out in hopes to get the water out. I appreciate the comments just looking to find out what is missing that used to plug the other hole.
 
That is a drain hole for a cavity in the lower unit.--------------------Many lower unit cavities fill up with mud / sand / debris and then do not drain properly and results in freezing / cracking.--------------Do not plug that hole !!!-----------Remove the lower unit / inspect and make sure the cavity is clear.-------------Leaking oil could be from the exhaust or lower unit oil.------Pressure test or have it tested by a shop to look for gear oil leaks.
 
Thank you for the comments. Just seems strange to have that when it is submerged in the water. What keeps the water from going in? It seemed as water entered in and that caused the oil to expand and leak out. It is a two cycle engine so there is no oil in the upper unit, to my knowledge.
 
IT IS A CASTING CAVITY THAT NEEDS TO BE DRAINED !-----------Not strange at all.---------------Water enters from the top via the exhaust when motor is NOT running.------------Cooling water comes down from the top when the motor IS running.-------------This water needs to drain from the casting cavity.-------------------Oil that is mixed with the gas (some is not burned and comes out with the exhaust ) and would drain there as well. --------------2 stroke 101
 
Back
Top