Can I run my Mercury outboard without gear oil?

Matt129

Seaman
Joined
Apr 7, 2022
Messages
59
Hello everyone, I recently changed the water pump in my 1974 Mercury 1500 but I’ve misplaced the fear oil I bought so I’m going to have to buy more but I would like to at least test that I did the water pump installation correctly. Would it be alright to run the motor with a water muff without gear oil in the lower unit if I don’t put it gear?
 

ThomW

Chief Petty Officer
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Aug 8, 2016
Messages
615
No. I may be mistaken, but I am fairly certain things are still moving in the lower unit even when its not "in gear."
Don't run it without gear lube in the lower or you will may cause some issues with your gears. For the $8 gear oil costs, I wouldn't risk it.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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49,540
Hello everyone, I recently changed the water pump in my 1974 Mercury 1500 but I’ve misplaced the fear oil I bought so I’m going to have to buy more but I would like to at least test that I did the water pump installation correctly. Would it be alright to run the motor with a water muff without gear oil in the lower unit if I don’t put it gear?
for about 20 seconds before the bearings seize up and ruin your day. go buy more gear lube
 

Matt129

Seaman
Joined
Apr 7, 2022
Messages
59
I can't believe I just read this question.
Look, I’m 19 and I just got my first boat, sorry if it was a stupid question, I was just asking because I didn’t know the answer and I didn’t want to destroy my motor.
 

Silvertip

Supreme Mariner
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Sep 22, 2003
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28,771
I agree that if in doubt, it's better to ask the question. But on the flip side is the thing called logic! If the engine was designed to run without gear oil, why did they design it to run in gear oil. That also applies to the engine, transmission, differential, transfer case and lots of other rotating moving parts in cars, trucks, and boats. Finally, you do not prove the water pump impeller was installed properly by testing with muffs because you are using house water pressure to force water through the system. Even with a bad pump water will be expelled from the tell tale port. You run the motor in the water or in a test tank to provide the pump is indeed moving water.
 

JimS123

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Jul 27, 2007
Messages
8,162
Look, I’m 19 and I just got my first boat, sorry if it was a stupid question, I was just asking because I didn’t know the answer and I didn’t want to destroy my motor.
I apologize if my comment was offensive. It's just my upbringing. My Dad did all the oil changes on his cars by himself and he taught me that good oil was important. At age 16, when I got my driver's licence, changing the oil was my responsibility. That same year Grandpa gave me his outboard motor and taught me about oil changes and stuff.

I just thought that the necessity of lubricating moving gears was kinda intuitive.
 

Silvertip

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Sep 22, 2003
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And I'm like Jim in that I learned by reading and watching long before there was an internet (and even TV). Yes - I'm older than dirt. But, when my daughters began driving it wasn't just about stopping, starting and safe driving. They learned what gauges/indicators tell you, the importance of preventive maintenance and what the consequences are if you ignore them/it. As the mechanic in me preaches "pay me now or pay me a whole lot later" if you ignore a problem.
 

Texasmark

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Dec 20, 2005
Messages
14,666
I bought my first boat at 15. Didn't have a car but mom let me use hers. I didn't know s....from Shinola (a brand of shoe polish popular back then). So don't worry about it. Have a question, ask. If you don't like the answer or answerer, forget it and get on with your life. Good Luck.
 

JimS123

Fleet Admiral
Joined
Jul 27, 2007
Messages
8,162
Sorry to digress, but its a funny story.

Last year in college I met a nice girlie who didn't ever have a car. For graduation her Dad bought her a brand new one. She told me she was going to be verrrry careful with maintenance, and would test everything. Last time I talked to her she was going to check it all out.

She checked the oil dipstick and it was OK. But, OMG the radiator was almost empty, so she got the hose and filled it up. Then went on a drive to start the breakin.

The motor seized after a block and a half.

The problem was her Dad didn't explain the difference between a radiator cap and an oil filler cap.

The root cause of the problem was she didn't read the Owner's Manual.

It makes me mad that manuals are no longer supplied. The manufacturer's say nobody reads them, so no paper printing is a cost savings. The silly thing is that they are all available online, even for the old stuff. I recently downloaded a manual for my 1919 Evinrude Rowboat Motor - and it was even free.

Bottom line, though.......we all know something, but not everything. That's why forums can work to our advantage. Whatever we don't know, someone does.
 

Sea Rider

Supreme Mariner
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Sep 20, 2008
Messages
12,345
Most folks doesn't read any Owner's Manual at all specially Outboard Motors...

Happy Boating
 

Yegboats

Chief Petty Officer
Joined
Feb 20, 2016
Messages
518
I apologize if my comment was offensive. It's just my upbringing. My Dad did all the oil changes on his cars by himself and he taught me that good oil was important. At age 16, when I got my driver's licence, changing the oil was my responsibility. That same year Grandpa gave me his outboard motor and taught me about oil changes and stuff.

I just thought that the necessity of lubricating moving gears was kinda intuitive.
A lot of the younger generations aren't so lucky.
Real Men don't read Operator Manuals

until there is a Problem, which of course is Never their Fault
This is hilarious because I know you irl. Also you're the only person I've met that rivals my operator manual collection :p
 
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