1995 johnson 25hp water diverters

[wingster51]

I replaced water pump, head gasket,thermostat, and exhaust gaskets because son overheated motor. It seemed to be running fine but I decided to run in a test tank to see how the temp held up. It started getting hot on the head. The exhaust side just warm. I pulled the head again to look at the diverter tubes. All three of them are solid rubber. I remember reading something that said they had a hole in them. Mine are solid. They are oval and tapered. Can this be my overheat problem?

Can I run water through the head while it is off to check for blockage? Same with the block. Thats for the help

 

[racerone]

Water does NOT go through the diverters !-----They guide the water around the water jacket for proper flow / cooling.---Salt water motor ?-----Is the water 6" above the water pump in your test tank ?---How hot is hot.-----Can you put a number on it ?----Can you hold your fingers on it for 4 or 5 seconds ?----Will water sizzle on the head when you sprinkle it on there ?

 

[wingster51]

The reason I ask about the diverters is that reading some posts on here people were told that they had collapsed and replace with hose. The motor is not salt water used. I couldnt hold my fingers on the head for 4 or 5 seconds. too hot. I dont think water would have come close to sizzling. No it is not six inches above pump. About even. Thanks

 

[racerone]

Water has to be 6" or more above the pump !!----Retest or launch the boat and test run it with pump properly submerged.----Some of the simplest facts are the hardest for folks to understand.

 

[wingster51]

Please help me understand. I am not doubting what you say one bit but I am sure all of us have run our motors with muffs and it didnt overheat. That is what makes it hard to understand . Are you saying that is a dangerous thing to do? If it is I will no longer do it that way. These things cost too much to take a chance with.

 

[Joe Reeves]

Wingster...... In your first post, you state that there is no hole and that the water deflector(s) are "solid, oval, and tapered"!. There is no hole because it/they are squashed flat. In that condition, they have expanded sideways and are interfering with the circulation of the water. Yeah, I bet that thing got hot!... Replace the water deflectors as follows:

********************
(Water Deflectors)
(J. Reeves)

Water deflectors are actually lengths of 3/8" outside diameter rubber hose, installed between the top cylinder and any cylinder beneath it, and also between the bottom cylinder and the block. The purpose of the deflectors is to have the water follow a definite path around the cylinder walls. Unfortunately the deflectors between the cylinders will at times swell sideways due to either a previous bad overheating problem, or simply due to age and salt corrosion. This causes a water flow restriction which usually allows the water to cool sufficently at low rpms but not at the higher rpms.

This hose material can be purchased reasonably at any automotive parts type store if you care to make your own, or you can purchase individual deflectors at any Evinrude/Johnson dealership at a somewhat higher cost.

Removing and installing them can be a hassle at times, but not always. I use a sharply pointed scribe with about 1/4" of the tip bent at a right angle whereas I can reach in, jab the tip sideways into the rubber, then yank it out. It's necessary to clean the seating surfaces where the ruber contacts the block with a small rat tail file to eliminate salt deposits etc. When installing the new rubber deflector, coat the deflector and the metal surfaces with WD40 which will act as lubrication to allow it to go in as easily as possible.

Make sure that you insert something into that deflector area before cutting and installing the deflectors if you make your own so that you will be certain that they are the right length and also that they will be seated properly. Usually a very small amount will be left extending about the block sealing area..... simply cut the excess off with a single edge razor blade.
********************

 

[wingster51]

Hi Joe. I have one deflector between the top cylinder and the top of the water jacket. There are 2 between the bottom of the lower cylinder and the water jacket. All are tapered solid rubber plugs. They do not line up over a water hole in the block. No water could get into them if they had holes in them. They also dont line up with a hole in the head. Im confused

 

[racerone]

Water does not go through these diverters !

 

[Joe Reeves]

Okay... I retired in 1991 so your 1995 model will always be a bit in the future for me. However, there is no need for the deflectors to be a solid rubber stud as what I described in my database upload worked fine for many years.

That being said... look at the water passageways in the crankcase/block... there will be a small casting/ridge built into the block where the deflector lays up against it, preventing it from moving out of its designed location. Those ridges make it easy to pinpoint thr water deflectors location.

If possible, upload a close up picture of the block, head off, showing the entire water passage area.

 

[boobie]

Agree with Joe !!

 

[wingster51]

Ok I found a pic of the deflector called for in my motor at crowley marine. It is a solid plug. It is part 0335602. I used a valve packing puller.(corkscrew) to pull them out and they look good. I see the ridge you are talking about Joe. I will put into a garbage can full of water and report the results. Thanks

 

[Joe Reeves]

Wingster51.... With no intentions of offending you...... You appear to be in a rut and hung up on these "solid" deflectors you keep mentioning. If you want to spend an outrageous amount of $$$ on those short rubber components, that's your prerogative... but the 3/8" fuel line route is the more economically route to travel and has proven to be lasting unless overheated bad, in which case, the head has to come off anyway. However, suit yourself but don't try to sell me on those solid plugs as it's just a route the engineers make to keep their employment secure.

Now, you make no mention of having replaced those deflectors but in your last post (#11), you mention that you pulled the deflectors out and they look good... BUT... in post #1 you state "They are oval and tapered".

The deflectors are (and must be) approximately 3/8" in diameter (round) from one end to the other... not oval whereas they would be protruding into the water passage way.

 

[wingster51]

Not offended at all. I am just trying to learn. I certainly dont want to spend more money than necessary. I am just trying to figure out if the previous owner put the wrong deflector in. When I said they looked good I simply meant that they looked like the ones they sell at crowley marine as oem. I am not trying to offend you. You have been very helpful and are very knowledgable. I really appreciate your help. That being said I would gladly use the 3/8 hose if I thought it would work. The place the deflectors go has a distinct taper to it. When they are put in place the plugs take on an oval shape conforming to the space they are put in. Maybe this is a weird motor. Please take a look at crowley marine part 0335602 and part0335603 and tell me what you think.

 

[racerone]

1980 models to 2007 models used deflectors.----There is nothing weird about your motor.