Water in lower unit!

T

thunderhockey05

Recruit
Joined
Mar 11, 2010
Messages
1
I have a 25hp 2 stroke outboard from 1998. I drained the lower unit and there was quite a bit of water in it. I am wondering what some possible causes may be? I know there may be bad seals but I am not sure where to locate them or how to change them. Any help would be greatly appreciated. Thank You
 
achris

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: Water in lower unit!

Hi and welcome to the forums,

Start off by downloading a service manual for your engine.... Click HERE. The password for the file is ribforum.

There are 6 seals in a lower unit. 2 on the drive shaft, 2 on the prop shaft, one on the shift shaft and an 'O' ring around the reverse bearing carrier. You're leak could be any one of those.... Make up a pressure/vacuum tester and find out which seal is leaking, (Click HERE for details on making a pressure/vac tester) or replace them all, your choice.

The manual details all you need to know about removing the lower unit and replacing the seals....

Chris.............
 
M

Moody Blue

Captain
Joined
May 24, 2004
Messages
3,136
Re: Water in lower unit!

Achris forgot to mention the two simpler (cheaper) possibilities.

THere are two plugs in the lower unit, one for oil drain and one for vent. Often owners try to reuse the sealing washers under the heads of these plugs but they are really only intended as a one time use. They cost $1 each and that would be my initial approach.

Replaced the two sealing washers, refill with the proper marine gear oil then go for a long ride. Drain the oil and check for water intrusion then go from there.

I've owned two motors and both had bad shift shaft seals.
 
I

Intune

Seaman Apprentice
Joined
Mar 11, 2010
Messages
37
Re: Water in lower unit!

Thank you Achris! Those downloads are AWESOME! Just what I needed. Except, I don't have any excuses now for working on my own boat. ;)

Also a big thanks to Moody Blue, I was a plug sealing-washer reuser. :redface: Mine were squished flat & I had to scrape them off like a gasket. You saved me some $$$ & heartache down the road.

You guys rock!
 
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