90HP Water in Lower Unit

[JustSayin]

I have a 90HP 1983(ish) Johnson on a 16' Glastron I bought last year (First boat). It is getting water in the lower unit. I have chnaged the drain/fill plug gaskets, but it's still getting water. I have been changing the lower unit oil about every 6 hours of use (2-3 times out) which seems to be limiting damage. (No metal in the magnetic drain). I have noticed the the prop blade has a few dings in it. I'm guessing that chances are if the prop hit bottom if may have messed up the seal. Should I change it regardless since it's dinged anyway or is there something else I should look at/do first? I am fairly limited mechanically, enough to be dangerous, but that's it.

 

[Daviet]

Re: 90HP Water in Lower Unit

The best way to find a leak is to remove the lower unit and do a pressure/vacume test on it. There are a number of places that water can get in, the pressure/vacume test will find the problem.

 

[Monte1961]

Re: 90HP Water in Lower Unit

If you have or have had the filler tube for the lower end, You can use that to apply pressure. Set regulator somewhere between 12 to 15 psi. Submerge in tank or use soap and look for bubbles. Also, make sure you turn main and prop shaft while looking for leak. Best to do with no oil in lower unit. Good luck and post back with how it turns out. If it winds up being the shifter rod, I'll post on how to replace or someone else will!

 

[JustSayin]

Re: 90HP Water in Lower Unit

Guys-

Thanks for the quick reply. I love this site!

Daviet - Thanks, I'm not sure I'm that mechanically inclined just yet. Although these threads are so much help!

Monte - To be sure I'm understanding you: Drain all of the oil out of my lower unit. Install the upper plug. Connect the threaded oil filler tube. Connect tube to compressor, 12-15psi. Then either use soapy water in the same manner you would when finding a leak in a car tire. As far as submerging it in water, would that make it easier to identify the leak. I figure I could fill a large Rubbbermaid garbage can and just lower my engine in.

 

[Daviet]

Re: 90HP Water in Lower Unit

Yes, pump it up to 10-12 psi and submerge in a barrel of water. Make sure and turn the propshaft and driveshaft by hand, work the shift shaft also. That will make all of the seal surfaces react to the pressure and might make it easier to find the leak.

 

[Monte1961]

Re: 90HP Water in Lower Unit

JustSayin, If you listen to Daviet and even me, your sure to get it done!! Post back and tell us what you find!

 

[JustSayin]

Re: 90HP Water in Lower Unit

Guys - I will, thanks for the help! I'm actually bringing the boat home from the lake this weekend to do a 2 week cheepo restoration on it. I'll keep you informed on the motor and will open a thread for the resto. I'm going to catch a lot of crap on the resto thou, I just don't have the $ to do it 'right'. We'll see as I get into it thou, you never know!