Water Deflectors 1990 Rude25...Help!

Cofe

Lieutenant Commander
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Apr 23, 2009
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Had overheating problems::Replaced water pump, Thermostat, Head gasket, and then found the water deflectors were crystallized and deformed. I have read that they are made of 3/8 OD fuel hose, but my question is how long is a person to make these deflectors? Should you leave a space for the water to travel close to the head or to the back of the cylinder? and how much space? Or should these deflectors be the full length of the deflector area? There are 3 of these deflectors in the motor. Please see attached picture.(The 3 pieces of hose in the picture are just to show where the deflectors go). My manual doesn't say anything about these deflectors. Any suggestions would be great.
 

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Cofe

Lieutenant Commander
Joined
Apr 23, 2009
Messages
1,883
Re: Water Deflectors 1990 Rude25...Help!

I think I found the answer from a post made from Admiral some time ago. I believe from deduction, that analyzing the water flow path. I can make the deflectors full length. Ps. see the picture below. This is the lower right side of the motor where that deflector goes. Note that there is a small water passage behind the deflector. And it was plugged with impeller trash. This pic was taken with a mirror, upside down. Also read the letter from Admiral below.

If you didn't replace the complete water pump assembly, do so.

On bank running hotter than the other may have faulty water deflectors. See the following.

(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 sufficiently 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.
 

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