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1988, 25hp water jacket diverter question

steffco

New member
Are the water jacket diverters supposed to go the full length of the cavity they sit in or are they slightly shorter than all the way from the inside of the block to the head?
The person before me replaced the OEM diverters with pieces of 1/4 hose and the bottom 2 were charred but seemed to go full length whereas the top one looks to have a 3/16 gap on both ends? Sorry about the double post about my 25 got hot post but i did not want this to get lost as i am in the reassembly mode today. Thanks
 
(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.

Thousands of parts in my remaining stock. Not able to list them all. Let me know what you need and I'll look it up for you. Visit my eBay auction at:

http://shop.ebay.com/Joe_OMC32/m.html?_dmd=1&_ipg=50&_sop=12&_rdc=1
 
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