1998 Johnson 90hp crossflow

bwilson2626

Seaman Apprentice
Joined
Aug 12, 2018
Messages
32
Hello everyone, I'm new here, but am very glad to find this space!!

What brought me here is I am hoping to find some guidance on an issue I have with my motor. I recently removed the heads & exhaust cover plates. Cleaned the piston tops, fixed a broken bolt, and replaced everything as per my manual. Right now there is about 50% less water flow through the right side of the motor as opposed to the left. The reason I know this is when I started the motor after assembly, it ran hot after a few minutes. Did a little research and decided the thermostats were the cause. That was likely the issue because they were both in horrible condition and mostly plugged up. I wanted to flush out the system, so with the thermo cover still off, I ran the motor (very breifly). During the run time, I noticed the right side port (that would flow to the thermo housing if installed) had about half the flow of the left port. I have since soaked & flushed the motor with salt terminator multiple times, with no visible improvement. I'm not sure if the issue was happening before dis/re-assembling, which leaves me guessing if i did something wrong while assembling the head & gasket. The gasket was stamped with an arrow & directions to point arrow to exhaust cover, which is what I did. I run in salt water almost exclusively, and flush the engine EVERYTIME with salt away or terminator.

I am a long ways from being a mechanic, but am fair with a wrench. I do all the maintenance myself and hope to finish this without taking it to a shop. Any advice??
 

interalian

Commander
Joined
Jul 23, 2009
Messages
2,105
If you have a look down the forum page you'll see you're not the only one with this same concern. As you say it's a crossflow, did you notice the two rubber plugs in the water jacket when you had the heads off? If swolen, the one in the center can block flow.
 

Attachments

  • photo291483.png
    photo291483.png
    135 KB · Views: 0
  • photo291484.png
    photo291484.png
    131.9 KB · Views: 0

bwilson2626

Seaman Apprentice
Joined
Aug 12, 2018
Messages
32
I believe that is spot on! They looked to be in good shape, but were definately swollen, compared to the one in the "good" pic. Is there a name for those little devils?
 

interalian

Commander
Joined
Jul 23, 2009
Messages
2,105
They're called 'water passage deflectors'. 322411 on the BRP parts list.

Some use fuel line with a suitable outside diameter. I might try that but I'd want to put a plastic plug in the inner diameter to keep them from collapsing.
 
Top