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1989 Johnson 150 hp J150STLCEM problems

C

Chuckl77

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So the story up until now....We bought this boat knowing it had some issues with overheating. We take it to a local shop that agreed to work on it. VRO was already bypassed and running on mixed gas. Turns out overheating is just some clogs that the shop cleaned out, but they recommended replacing the VRO unit and all fuel lines, and cleaning out the tank. We say clean the tank, replace the fuel lines and tune it up and see how it runs. They supposedly do all of this and say it is running fine, take it out and try it, however they still recommend replacing the VRO unit for another $750. $600 later we pick up the boat and take it out for a test run (minus the new VRO). We put it in the water and the motor will not run for longer than 30 seconds, usually a lot less. We take it back to the shop and they tell us that the fuel side of the VRO is bad now and want to replace it for $1250. They say they are unable to get a rebuild kit for the fuel side of the VRO and can only replace it. We decide to take matters into our own hands.

We ordered the VRO rebuild kit from this website, and I was able to rebuild it and put it back on. Now the motor will start and run, however it has a very rough low idle, and will only run for a few minutes and dies out. We have discovered that it seems to not keep vacuum on the fuel line. it will use all the fuel we have primed up to the motor with the primer bulb, but will not maintain. If we re-prime with the bulb, it will run again for a few minutes and die again. Any ideas on this? Is this something the shop missed/screwed up? Is it something I missed/screwed up? Is it something else all together? I am mechanically inclined, but this is my first time working on a outboard, any help would be appreciated!
 
Your story indicates that the fuel pump is not pulling fuel...i.e. bad fuel pump, even after your attempt to rebuild.
You could have failed at the re-build attempt...I don't know.

You might not have any pulses coming from the crankcase to drive the pump....

But at any rate, the fuel pump is not working.

Experts will know this....Can he use the old dual fuel pump setup that was on older crossflows instead of the VRO setup he has now?
Even that might be just as expensive to set up...

Another option is to buy a fuel pump only style VRO pump, and mix your own gas in the tank. That pump is less money than the oil-mixing VRO.

It's part number is 5007422 (I think....if not it is 5007421).

Look here for Fuel pump options. http://www.maxrules.com/fixomcvro.html#VROkit
 
I'd avoid that "local shop" like the plague.... sounds like they generate their own work load.

You don't say...... Did that engine run at all after you bought it? Did you water test it before you took it to that shop?

Average compression, even new would be 95 psi (starboard bank) - 90 psi (port bank). Try another gauge. NOTE that compression varies with the cranking speed... slow rotation = low reading!
 
Last edited:
joereeves said:
I'd avoid that "local shop" like the plague.... sounds like they generate their own work load.

You don't say...... Did that engine run at all after you bought it? Did you water test it before you took it to that shop?

Average compression, even new would be 95 psi (starboard bank) - 90 psi (port bank). Try another gauge. NOTE that compression varies with the cranking speed... slow rotation = low reading!
Click to expand...


We have definitely decided to be done with the "local shop"!

As for before buying, we were told that it would start, but kept giving an "overheat alarm" and shutting down. However we only went by what we were told, and since we had so many irons in the fire at the time, we decided to just let the "professionals" find the problem and fix it. Once we realized we were paying $100/hr for guess work, we decided we could do that much cheaper ourselves.

Regarding the compression, I am going by what was listed on the paperwork from the "local shop", however I am finding several things that were listed on the paperwork that we paid for, that were not done or only half done, so I will track down a compression tester myself and check that this weekend, along with checking for good spark. That is 7/16" correct?

While I am working on it this Saturday I figured I would check all the hoses and make sure I didn't knock any vacuum lines loose in the process. I will also re-inspect the rebuild on the VRO unit and also inspect the housings closely for any cracks or weakness that might be causing problems.

Is there anything else I should be looking for or focus on while I am there? I also saw that daselbee mentioned pulse from the crankcase. Is that a vacuum pulse or an electric pulse?
 
Vacuum AND pressure, alternating, comes from a fitting below the lowest carburetor, and connects to the pulse port on the VRO.
It is a large piece of fuel hose...3/8" ID I believe.
Look at the link I provided...it shows which nipples on the VRO are what.

It is what drives the VRO fuel pump. Oil is mixed internally to the VRO, all by mechanical action of pump operating.

No electrical involved to operate. The electrical is for NO OIL sensor only.
 
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