1993 Johnson 150 Oceanrunner

[jaythebaron]

Hi,

I have a 1993 Johnson 150hp Oceanrunner that will not stay cranked. When I pump the primer bulb it fires up fine, then after a few minutes it dies. I just replaced the inline fuel/water seperator and I couldn't find any obvious leaks in any fuel lines. I notice after a few minutes of running that I can pump the bulb to keep it running. Any ideas on how to keep this thing running so I can get out and enjoy this weather? Thanks in advance.

 

[SparkieBoat]

Re: 1993 Johnson 150 Oceanrunner

you either have a bad fuel pump or a bad fuel line/connector that is sucking air. remember that your fuel line from tank to engine is in vacuum ..meaning if it leaks it will not leak fuel it will suck air. make sure to fix your problem because running your motor like this can damage it.

 

[daselbee]

Re: 1993 Johnson 150 Oceanrunner

Sparkie's right. Fuel pump. Pumping the bulb whiile running is a sure sign.....

 

[jaythebaron]

Re: 1993 Johnson 150 Oceanrunner

Thanks guys for your replies! I'm jut now getting a chance to take a good look at things. I too am pretty convinced that my VRO pump (modified to mix 50:1 instead of injecting oil) is shot. Does anyone know what the part number for the VRO pump is? Do you know if a OMC VRO Pump Replacement # 5007423 will work on my engine?

Thanks again for the help!

 

[daselbee]

Re: 1993 Johnson 150 Oceanrunner

See here:

http://www.maxrules.com/fixomcvro.html

The 5007423 is a three wire pump...you want 5007420 for automatic oil mixing, or 5007422 for no oiling.

Or put in a kit for the fuel side, and see if that does it.

 

[jaythebaron]

Re: 1993 Johnson 150 Oceanrunner

Thanks Daselbee, I have taken the alarm plug off and have capped the oil portion of the pump. I am currently mixing a 50:1 gas to oil ratio. Now I'll go ahead and ask the no brainer. I did notice that the cap on the oil side of things has dry rotted could this be letting air into the system to where I would have to keep pumping the bulb so the motor stays running? Also, If I do end up having to purchase a new pump, would part number 5007423 work with my motor since I am not using the oil portion of the pump? Thanks again for the help!

 

[daselbee]

Re: 1993 Johnson 150 Oceanrunner

There should never be any air leaking into the system, but I kinda doubt that a "dry rot" air leak/seepage could introduce enough air to keep it from pumping ANY fuel.

This pump is supposed to click every time it "unloads" a gush of fuel to the carbs. If it is not clicking at idle...maybe once every 2 -3 secs, then the air diaphragm on the fuel side is leaking OR the pulse limiter/hose has a blockage or is split and off. You can definitely hear it click, but you can use a screwdriver as a stethoscope if needed.

Also, I had one once that the screws were loose on the back side...leaking at the air diaphragm. Tighten til snug, then 1/8 turn more.

I personally would use the 7422 version that is a no oiler. Actually, I would probably put in the air motor side rebuiild kit first, assuming the pulse limiter and hose checks out.

You should be able to blow and suck air on that line with ease. Air goes both ways. Only when a huge pulse of air hits the limiter (as in a crankcase backfire) will the pulse limiter kick in and keep you from blowing out the fuel pump diaphragm.

 

[jaythebaron]

Re: 1993 Johnson 150 Oceanrunner

Thanks for the help everyone. I found a used VRO pump in new condition from a local mechanic for $150. After installing it, she ran for about 30 minutes on the ears without dying (I shut her off, gas is expensive these days!). The motor even seems to be "peeing" stronger too.

Now for my final thought/question: The VRO pump I bought came with the mounting plate (primer not included). Does anyone know the name of this part? I would like to put it on Ebay to reclaim some of the money I spent on the pump.