Water pump issues? Johnson 120

PSiedTSi

Seaman Apprentice
Joined
Jun 12, 2007
Messages
36
87 or 88 120 V4. Just started my boat up for the first time today, and it seemed like the stream of water was not very strong, more like a drip. I had the ear muffs on so that could be part of the issue, but it concerned me because one side of the motor was quite a bit warmer than the other side(it was actually cold after 5-10mins of running). I pulled a line off of the top of the cylinder(little box on top of each bank?) that looked to be a water line and it was dry going across to the other side of the motor. It also concerned me that it was leaking water above where the gear oil reservoir is located. Could that be why there is so little water coming out the outlet? Just want to get everything in good shape before I throw it in the water.
 

PSiedTSi

Seaman Apprentice
Joined
Jun 12, 2007
Messages
36
Re: Water pump issues? Johnson 120

Just did a bit of searching, and it looks like the water pump is in the lower unit, is that correct? It seems like the water is leaking out of the top of the lower unit when the muffs are on. I would assume thats not a good thing lol. I've had it "winterized" every season so I'm going to assume its not because of cracks, but just a gasket issue?
 

jesseoshea

Cadet
Joined
Jul 19, 2009
Messages
11
Re: Water pump issues? Johnson 120

My 120 pisses weak on the hose as well, but it pumps much better in the water. If your water pump hasn't been replaced in the past few seasons, it is cheap insurance. The complete kit is usually $65 from a local dealer. It is pretty easy to replace and should take no more than an hour. My boat also had an issue where one side was much cooler than the other, but it was just the thermostat stuck open. They are also relatively cheap and easy to replace. You just remove the four 3/8" bolts that are around the hose you were referring to on the top of each head. I would suggest replacing both at the same time.

Goodluck!
 

PSiedTSi

Seaman Apprentice
Joined
Jun 12, 2007
Messages
36
Re: Water pump issues? Johnson 120

Yeah I don't think the water pump has been done since I owned the boat. Sounds about right about the thermostats, so that should be pretty simple. What is the device the line runs to from the water pump(before the it goes to the thermostats) up on the side of the motor? I have zero knowledge of marine lingo, but have done plenty of work on cars.
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: Water pump issues? Johnson 120

1st kritters like to make nest in the tale tell hose. use weed eater line to clean it out. Muffs have to be center on the intake. changing the tstats is simple. sounds like a first try. but if the water pump has not been changed it is time. before you do real damage. also could be deflectors in the cooling system. i would do tstats and water pump.
 
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