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1988 Johnson 90 hp Water deflectors check and clean

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BallisticRenegade

Member
On a Johnson 1988 90 to clean the water passages in the head what do I need to remove? part 30 the water jacket and 29 the gasket ? Or do I need to also remove 28 the cylinder head and 27 the head gasket? I am planning on replacing the gaskets of what it is I remove. is there a gasket sealant I should use to rebuild it?
46490.jpg​
 
The cylinderheads ( 28 and 40 ) have to come off.-------------And I am saying this based on more than 40 years experience !
 
Is this a good project to take on to verify/ PM the cooling efficiency of the motor? 1-10 how tough is the job? Gaskets and bolts do not seem over my ability however if I am interrupting rings and sleeves I would reconsider. Thoughts?
 
You really need to understand that this is a simple job-----You will not be interrupting rings and sleeves !!!!!!!
 
That is great news Racer, Thanks for the info.

I do have questions for someone who has done this.
Is there anything else involved other than replacing the gaskets upon reassembly? Do these gaskets require any additional seal spray or adhesive?
What do you clean the passages with?
How can you tell if the deflectors are bad and what do you replace them with? They are not pictured unless it is part 10 above?
Anything else to do as long as I am this far in to the head?
 
You better be very, very careful. You are likely to break some bolts. And it is NO FUN trying to get them out.
Remove #30, held on by #33, without breaking any bolts, and you will be very lucky.

EDIT:
Upon re-assembly coat the threads of all the bolts, head bolts too, with a product called Permatex Avation Gasket sealer.
It is in a white plastic bottle, with brush in lid, and is a gooey brown liquid. It will make removal of the bolts in the future much much easier.
It is available at all autoparts stores.
 
Last edited:
Well...one other thing.
I am not real sure on your motor, but on some V4s the ignition coils are bolted to the heads.
When you remove the coils, leaving the wiring attached, you will lay the coils out of the way, and the remove the head.
When re-assembling, it is very very easy to swap the position of the coils on the head.
This results in the ignition being highly fouled up.

Mark the coils in a manner that makes sure you put them back in their original position.
 
I’m just about to do this myself. Do you have the part numbers or specific names of everything you replaced? No Johnnyrude dealers close, so I need to order online.

thanks!
 
????----Near the top of this page.----Square with ------engine diagrams---------Click and click some more to find the part numbers !!!
 
NorCalAndy said:
I see the diagram numbers, but not the part numbers. I need a number I can find online.
Click to expand...
Go here: http://www.marineengine.com/parts/parts.php

drill down by model # or find your engine by year, HP, and model. Click on the link for Cylinder and Crankcase and you'll see a parts diagram. Find the number for the parts you need then scroll down and find them. There you will see the part# that coincides with the diagram number.
 
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