25hp Mercury no water flow out of the hose

wolfee

Petty Officer 3rd Class
Joined
Aug 20, 2007
Messages
77
I was going to take the boat out last week and started it up in the driveway with a water hose attached. (I've done this multiple times in the past, no issues) I got the motor started and I was letting it heat up to see how the idle was and I noticed smoke coming out of the small hose in the back that's supposed to pee-out water. I immediately shut the motor down, and checked the drain hose. It was completely blocked up with mud (mud wasps I guess). I cleaned out the hose and was able to blow air through the hose, put it back on and started the motor up again. I had smoke coming out of the prop area and nothing coming out of the hose. Granted I didn't let it run for long, probably less than a minute, but it looks like something is still blocking water flow. I ordered the service manual "Service Manual, Engine specifications, maintenance, repair procedures" from Mercury Outboards when I rebuilt the carb, so I have their manual. Problem is I don't know what I'm doing as far a water flow goes. Any help appreciated!!
 

flyingscott

Fleet Admiral
Joined
Apr 8, 2014
Messages
8,159
Need a serial #. You should have had water coming out of the prop pull the lower unit and check the impeller. Make sure the 2 washers are on the impeller
 
Last edited:

ondarvr

Supreme Mariner
Joined
Apr 6, 2005
Messages
11,527
The pee tube is just an indicator of flow, if it's blocked by bugs or gunk it will have no affect on how the motor cools. It becoming plugged is common.

​If steam was coming out there are issues other than the tube being plugged, same with no water at the prop.
 

wolfee

Petty Officer 3rd Class
Joined
Aug 20, 2007
Messages
77
Serial #: OC196683 I didn't really notice if there was water coming out of the prop or not because of the water spraying out from the hose/ear muff type clamp covering the water intake. There was definitely smoke coming out from around the prop though.
 

ondarvr

Supreme Mariner
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Apr 6, 2005
Messages
11,527
Smoke should be coming out from the prop, not from the pee tube.
 

wolfee

Petty Officer 3rd Class
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Aug 20, 2007
Messages
77
Ok, is this something I can do by tilting the motor up (short shaft) while still mounted on the boat or am I going to have to take it off?
 

flyingscott

Fleet Admiral
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Apr 8, 2014
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8,159
Yes you can take the lower unit off of the motor with it on the boat. Since you are checking the impeller replace it right away
 

Fishaddicted

Cadet
Joined
Apr 7, 2017
Messages
16
I had problem with muffs on to i used a very clean garbage can and ran motor because it barely spit with muffs on plus a can simulates the motor being in water but if no water after can use check your impeller its an easy swap
 

wolfee

Petty Officer 3rd Class
Joined
Aug 20, 2007
Messages
77
I couldn't find this post and started a new one, please ignore this post. Sorry about the confusion.
 
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