Guests - If You want access to member only forums on HSO. You will gain access only when you Sign-in or Sign-Up on HotSpotOutdoors.

It's easy - LOOK UPPER right menu.


    You know what we all love...

    When you enchant people, you fill them with delight and yourself in return. Have Fun!!!

Sign in to follow this  

Lower unit air test?

Recommended Posts

I found that my 89 johnson 25 hp motor looks to have a small leak in the lower unit. This has happened before and I have had it air tested. Which it passed all 3 times. It only seems to happen when it get really cold or warm in my garage. Could this just be seals expanding and contracting? I was wondering how a guy would go about doing an air test for yourself. Drain the lower unit oil and hook up a valve and gauge to it and pump up with a compressor I would think. What kind of psi do they test at?

Thank in advance


Share this post

Link to post
Share on other sites

They only need about 12-15 lbs and NO more. You are going to need a small pump, low presure guage and correct fittings. On my set up, I even have a shut off between the pump and guage. Are you sure its gear lube and not unburned oil from the exhaust?

Share this post

Link to post
Share on other sites

No Im not positive. I was kind of wondering if thats it because it has passed 3 air test in the last 8 years. It doesnt really stink like gear lube either. Should I use it a few times and then check/change the gear lube and look for signs of water?

Share this post

Link to post
Share on other sites

If its real stinky and black, its more than likely from the exhaust. Keep an eye on it.

Share this post

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

  • Your Responses - Share & Have Fun :)

    • Yup.... 6 & 4 for Lead.... 4 & 2 for steel
    • I ended up framing my house, putting on the T&G , and then spray foaming back against the interior, which may be why I am not seeing any movement... I also used pine vs cedar
    • I agree with the guy who agreed with the other guy.
    • Just wait till they come up with the remote submarine drone with 3d high resolution camera that can see through algae and milfoil and transmit to your eyewear in 3d.   I struggle with properly tying a berkley knot......
    • I agree with rundrave. #4 early and #2 shot later in year
    • Yes, 5/16 T&G I installed last fall. I did the same, but I see this summer it's starting to buckle  
    • Adding a 4th wouldn't do much IMO. The map screen is already too small to be useful when screen is split in 3. I added a Helix 7 G2N to use as a map screen. Networked with other 2 units
    • I could always go and spend more money on an additional unit but some of it is like Floyd said. I have a hard enough time watching one screen. I have the app on my phone. I think that lowrance has the ability to split the screen into 4. I just can't believe I'm the only person who would like to see this but maybe I am. It may not be as big a deal once I get more familiar with the unit. Right now I like to look at all the screens to help discern what it is im seeing on the screen.  I appreciate the input!     
    • Males were on the beds last night on a lake here in the metro. Not my deal, so I let 'em be. Which means I didn't catch much at all compared to last week.   Oh well, be a couple weeks before the summer patterns start happening. Already a hint of cottonwood floating on the water though. *booooo*
    • I would agree with Purple.   Just add an inexpensive unit of your choice for the maps.   You could even use a cheap tablet with the navionics app on it for the mapping, if money was an issue.     You can buy a 7 inch generic (RCA) tablet for around 50 bucks.    A few bucks more gets a holder.