2003 Johnson 90hp fuel pump

dmac0056

Recruit
Joined
Jun 8, 2021
Messages
4
I have a 2003 Johnson 90hp (model J90GLSTA). It's been garage kept and serviced properly since the beginning. The previous owner never had any issues and the only parts he's had to replace is the plugs and impeller. I've only taken the boat out about 5 times since I purchased it. Everything ran smooth, no issues at all. The motor always starts on the first try, maybe 2 if it's been a while. Last month I took it out and it ran fine. Got back to the launch, and I'm idling at the dock while my buddy backs up the trailer. I put the motor in gear and it starts smoking heavily and I didn't see it peeing. I shut it off and got it loaded. When I got home, I hooked it up to flush the motor. Took a few tries to get the motor started, and when it did, it smoked out the whole neighborhood. It was peeing though. I ran it for a bit attempting to troubleshoot, but no luck. I noticed that the primer bulb on the oil tank was rock solid. But the bulb would spin between the two hoses. I've never seen a primer bulb do that. I asked around for possible solutions and was advised that the heavy smoke could be because of the oil injection pump going out. It was suggested to replace the VRO or bypass it and premix. Due to my work schedule, I haven't been able to work on it until just recently. I ordered a new oil tank and installed it with fresh oil because I didn't like the way that old one was acting. (Full disclosure: mistakes were made, but I didn't realize it until a few days ago.) I installed the fuel tank and ran the electrical connection and the oil line to the motor. Then I filled the tank with fresh oil. Then I primed the bulb. I didn't realize I should've primed the bulb until oil comes out of the end of the hose and then connect it to the motor.

After the new tank install, I hooked it up and tried to turn the motor over. It took about 20 tries to get it started. It turned over a few times and immediately died. When it finally did start and stay on, it smoked out the whole neighborhood again. Again, due to my work schedule, I put it away and it sat for a few days. The next chance I got, I pulled the plugs and all 4 were soaked in oil. While I was checking that, I noticed oil in the bottom of the cowl. I also noticed a bit of oil dripping down the foot. After researching about the VRO, and looking for a replacement, I decided to take the VRO off of my motor to check for leaks or cracks. I've never worked on boat motors before, but I know they can be costly, so I took my time researching and waiting to get the nerve to pull the VRO. Today, I got it off and gave it a good look. I do not see any cracks on the unit, or any of the hoses. All of the hoses appeared to be securely connected. I'm not 100% sure that the VRO is the issue. I was advised to put the VRO back on and run a bit of mixed gas through it without the oil line connected, but I managed to break off one of the fuel outlet nipples from the primer solenoid, so now I have to order that repair kit first. After I took the VRO out I cleaned up the oil that was inside the cowl.

My question is this, does this sound like the VRO pump is the problem? That's a pretty expensive piece to replace, and I really don't want to be wrong. Also, if all of the hoses are in good shape and were connected properly to all the fittings, what else could be the cause of oil being in the cowl?

Additionally, I've been reading multiple forums about replacing the VRO pump and bypassing with premix. It looks like the crowd is split on this topic. The VRO pump on my motor is part number 5004554 (there is a sticker attached to this part with this part number). Through my research, it looks like this part was superseded with part number 5007420. I have not been able to find a standard fuel pump to purchase and replace my pump with to bypass the VRO for this motor. I have found them for 90 degree motors, but not the 60 degree motors. Any suggestions and input welcome.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,767
The VRO pump is easy to work on.-----Invest in a manual and take it apart.-----Inspect carburetors floats and float valves as well.
 

saltchuckmatt

Commander
Joined
Jul 19, 2019
Messages
2,836
If I remember right there is a check valve that can go bad and your carbs flood with oil. The test was to remove the cap on the oil bottle when running and it should clear up...

Been awhile since I worked on one but open up a float bowl and see if oil flows out (no gas)

If that's the case, that's your problem.

If your going to just run 50 to 1 in your tank all you do is remove the oil line and plug it, also remove the alarm wire. Existing pump without the oil line still pumps the gas.
 

dmac0056

Recruit
Joined
Jun 8, 2021
Messages
4
If I remember right there is a check valve that can go bad and your carbs flood with oil. The test was to remove the cap on the oil bottle when running and it should clear up...

Been awhile since I worked on one but open up a float bowl and see if oil flows out (no gas)

If that's the case, that's your problem.

If your going to just run 50 to 1 in your tank all you do is remove the oil line and plug it, also remove the alarm wire. Existing pump without the oil line still pumps the gas.
Thanks for the reply. I've never worked on engine internals before. Carb work is definitely new to me. I'm assuming you mean open the float bowl while the engine is off??

I just found and purchased the service manual for this motor, so I'm sure I'll be able to handle at least SOME motor work confidently. I would really like to figure out what the problem is before spending $600+ for a new pump, especially if that's not the problem.
 

saltchuckmatt

Commander
Joined
Jul 19, 2019
Messages
2,836
Drain screw on the float bowl. If it's full of oil and no gas your half way to solving it.
 

flyingscott

Fleet Admiral
Joined
Apr 8, 2014
Messages
8,199
When VROs go bad they tend to over oil the motor. Go premix or take the pump apart.
 
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