2003 Johnson 90hp (J90GLSTA)

dmac0056

Recruit
Joined
Jun 8, 2021
Messages
4
Sorry if this is redundant. This is also my first issue with a vro, and I too just want to make sure I do everything correctly. I have a 2003 Johnson 90hp (J90GLSTA). I need to replace the vro. The part number I came up with is 5004554. Am I understanding correctly that the part number on the pump itself is 5004554, but the kit which contains the pump and fittings is 5007420?
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
37,793
How did you determine that VRO is bad?-----They are easy to take apart for inspection / repair.----And new ones are over priced in my opinion.
 

dmac0056

Recruit
Joined
Jun 8, 2021
Messages
4
The last time we took the boat out it started smoking severely. Loaded up and took it home. Put the muffs on to flush the motor and the same thing happened. Started researching, and asked a few folks what were the possible problems. Watched some videos on the fuel/oil delivery system, and purchased and read the SELOC manual fir my motor. Took the cover off of the motor and took a look around. Noticed some oil pooling at the bottom of the engine. Took the vro off for inspection and noticed oil in the carbs. Cleaned up the oil at the bottom of the engine, and cleaned the vro, put it back on. It was dry and clean when I put it on. Capped off the oil line, unplugged the harnesses, and ran 50:1 mix from a portable tank. The smoke subsided quite a bit. I noticed there was oil on the front of the vro again. I've checked the fuel line for leaks, didn't see any.

Now there's no water coming from the tell tale. I ran it for a few minutes, and still no water. I've checked the tell tale, and it's clear of obstructions. Unscrewed the tell tale and hooked up my water hose to it to flush the motor. Barely cracked the valve and gently ran some water through it. Water comes out of the foot with ease. I'm thinking this issue is going to be the impeller.

This is a great motor, been garage kept its whole life, and used moderately (no hot dogging). I just want it back to the working condition it was in when I bought it a few months ago.

**edit**
I forgot to mention when I got it home that day when it started smoking heavily, it took an act of congress to start it to flush the motor. That never happens. It always starts on the first shot. The plugs were fouled. Changed them all when I did the premix test and fired it right up.
 
Last edited:

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,834
Air leaks into the gasoline side of the fuel system (at the main strainer, water separator, fittings, etc) cause the OMS pump to overpump oil causing heavy smoking. You might check that prior to buying a new pump.

Thermostats do not last forever and can get debris in them.

Obviously rebuilding the waterpump is a good idea.
 

ct1762@gmail.com

Master Chief Petty Officer
Joined
Jan 17, 2019
Messages
858
why not simply take the pump apart to examine the diaphram to see if its cracked and as suggested air leaks will cause it to pump faster? if you are already mixing 50:1 you can always just convert it to a non-OMS pump premix setup as well. both are equally simple. instead of buying a new OMS, they sell OEM rebuild kits for 1/10th the price of a $500 unit. i have one for $200 OEM brand new in the box if interested (complete OMS pump that is).
 
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