Need help with tube deflectors

btrimm30

Recruit
Joined
Jun 24, 2010
Messages
1
I have a cooling problem with 25 hp johnson and think the problem may be the tube deflectors in the cylinder head. We pulled the 3 old ones out, but one of them was only about 1 inch long going about a half way into the cylinder and another one had a pin shoved in it. What are they suppose to look like??
 

Cofe

Lieutenant Commander
Joined
Apr 23, 2009
Messages
1,883
Re: Need help with tube deflectors

If you look at the area where the deflectors go, there is a raised bump in the groove. That is where they stop. When I did mine, there was a bunch of trash behind the lower right deflector. I think it was impeller rubber. You will need a mirror and light to see it. There shouldn't be a pin in any of the deflectors. Here is a article J. Reeves wrote some time ago.

(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.
 

ezeke

Supreme Mariner
Joined
Sep 19, 2003
Messages
12,532
Re: Need help with tube deflectors

They are supposed to look like the ones shown here: http://www.iboats.com/Johnson-Deflector-Hose/dm/*******.450661775--**********.469502269--view_id.271462

It's very important to use hose with an ID < 1/8" or the hose will collapse and block the cooling passages.

18-0892.jpg
 
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