Lower Unit Oil "Burping" question

rtpassini

Chief Petty Officer
Joined
Nov 27, 2008
Messages
508
So I changed the oil in the lower unit for the first time. 85 evinrude 70hp.

I had read about burping it.

Fill it up until it flows out. Then put the vent screw in, pressurize it, and crack the vent screw until air/oil pushes out.

After doing that, I then realized...how am I going to get the lower screw back in when I disconnect the pump?

So I did it as quick as I could. Not a lot came out....about enough to "cover" (it sort of shot out and splashed my hand) half my hand.
Am I okay? Should I redo it?
Thanks for any help!!!
 
Joined
Oct 22, 2007
Messages
2,598
Re: Lower Unit Oil "Burping" question

You're fine, but you burp a baby, not a gearcase. All you need to do is fill until oil flows out the vent hole, install and tighten the top screw, then remove the oil pump fitting and install the bottom screw. You might lose a teaspoon or two of oil doing this, no big deal.
 

Rick.

Captain
Joined
Jul 30, 2006
Messages
3,740
Re: Lower Unit Oil "Burping" question

That's a new one on me too (burping). As stated above is the only way I've ever done it. Best of luck. Rick.
 

bonzoscott

Senior Chief Petty Officer
Joined
Jul 26, 2008
Messages
745
Re: Lower Unit Oil "Burping" question

I don't know if it's entirely "fine". What I gather as "pressurizing it", you effectively put a big bubble in the lube then it started rising UP. I'm not sure all of the air came out when you unscrewed the pump. To be safe, I would start over. Drain it in a clean pan and add it back to your pump jug. Refill as mentioned above. But maybe you pressurized it with more oil going in (don't know), but the word burp means air (or gas).
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,677
Re: Lower Unit Oil "Burping" question

Nah, Just pump it in the bottom drain vent until oil flows out of the top vent, w/o any air bubbles. Stick the top plug in and tighten. Now as quickly as possible remove the pump and plug the drain hole.

The OP is likely fine. He could add a little more from the bottom, just to make sure. Any air in the gearcase will have made it to the top by now.
 

Yacht Dr.

Vice Admiral
Joined
Feb 26, 2005
Messages
5,581
Re: Lower Unit Oil "Burping" question

I was told to pump the lube Slowly .. Possibly even waiting 10 minutes or so after the top hole starts to weep then see if it takes any more lube.
 

71Windsor

Petty Officer 1st Class
Joined
Jun 25, 2008
Messages
286
Re: Lower Unit Oil "Burping" question

air moves pretty quick even through gear oil all should be fine without waiting extended periods of time.
 
Top