94 Johnson VRO2 Fuel Pump testing & Replacement with OMS

[CoastalPete]

Motor (94 Johnson Ocean Runner 225) stalls under load (over 1000 RPM's) while in water, rev's up fine out of gear, tried lots of stuff (clean fuel tank to motor, new filters, plugs, cleaned & rebuilt carbs, replace fuel pulse limiter, checked compression, spark & timing all ok), I am thinking I need to check fuel oil pump (VRO2), dont have tester or knowledge, thinking I should pull off boat and bring somewhere. Before I do, can there be something wrong with the pump even though I pumped the bulb while under load as it does nothing to improve it, actually, the bulb stays nice and hard, which makes me think its not the fuel pump. I do hear the pump click every 5-10 seconds, heard it should be more like 20-30 seconds.

Does this sound like a faulty pump even though the bulb is tight, no apparent air leaks? If so, should I replace with newer style OMS pump system, do I need a conversion kit?

PLEASE HELP!
Thanks,
Pete

 

[d.boat]

Re: 94 Johnson VRO2 Fuel Pump testing & Replacement with OMS

If your current pump has 4 wires coming out of it, you won't need to do any converting, the new pump will be "plug and play". If it has three wires, you'll have to do converting, but the new pump comes with a 4 wire conversion harness and instructions. (at least mine did).

As for the functioning of the pump and your problem, I'll leave that to the experts. Good luck.

 

[wilde1j]

Re: 94 Johnson VRO2 Fuel Pump testing & Replacement with OMS

You can measure the pump's gas output pressure (see shop manual for correct pressure - I would expect 3 to 6 psig at idle).

Reving motor in neutral tells nothing... don't rev over 2000 rpm w/o a load. If squeezing the primer bulb has no effect, likely as not, the fuel pump is fine.

How did you clean the carbs? Soak overnight in carb solvent, clean all orifices, etc, blow dry with compressed air and reassemble?

 

[CoastalPete]

Re: 94 Johnson VRO2 Fuel Pump testing & Replacement with OMS

Thanks for replying, what guage do I need to buy to perform output test a compoung guage? Was also thinking of unhooking pump linie to carbs and crank to see fuel stream.

Yes, pump up bulb and she stays hard during load so I was thinking not pump or leak which is why I cleaned and rebuilt carbs. The carbs looked good apart, but I still blew them out with carb cleaner spray and followed with compressed air, then replaced all parts and gaskets. The engine does seam more responsive in nuetral but still cuts out at 1000 RPM's?

What do you guys thik I should look at next?

Thanks,
Pete

 

[Dhadley]

Re: 94 Johnson VRO2 Fuel Pump testing & Replacement with OMS

If the motor is sparking on all 6, the jets are correct & in the correct places and the sync & link is right the stalling is a carb issue. By squeezing the bulb you become the fuel pump. If that makes no change then it's OK.

As mentioned before, if any cylinder(s) is not getting fuel then it's not getting oil either. Just be real careful.

 

[CoastalPete]

Re: 94 Johnson VRO2 Fuel Pump testing & Replacement with OMS

thanks, never touched the sync, not sure if I should or know how. Can a fuel pump be bad under load, even if by pumping the bulb it does nothing to improve it? Should I be looking at engine vacume or something like that?

Thanks,
Pete

 

[Sir Robin]

Re: 94 Johnson VRO2 Fuel Pump testing & Replacement with OMS

Been chaseing a problem not unlike this on my 94 e150 eleom. When i began,I thought there would be a UREKA! one shot fix.......So much for that! By reading these forums in search of my problem then looking at my motor in depth, it finally hit me that because it gave such great service in the past that routine MANTAINANCE was overlooked. My ALL OF A SUDDEN problem was of my own making! Here is what I found so far...........

ALL..... repeat......ALL as in 6, main jets were LOOSE one actually fell out the bowl drain screw when I opened to check for water
Fuel bulb was hard as a brick and almost impossible to pump
Fuel line leaking at tank
Fuel line letting air in at aux filter(is there a pattern forming here?)
So much for my iggnrance

Be sure to check link and sync . I KNEW mine was not moved....BUT and this is important.........
EVERY SCREW IN EVERY PLASTIC PIECE WAS LOOSE!!!!!! Timing to throttle had backed itself to the bottom causing bog at takeoff. Spark advance wobbled, so check ALL screws

GEE, I thought I took GOOD care of the old girl,,,,,........
Sometimes you may have a one of problem, but look under the hood at least once a season,.........
With the help of the people on this forum i was able to better understand the problems that might happen and a way to troubleshoot and fix them. These guys are GOOD here.

The DUMMIE dave

 

[CoastalPete]

Re: 94 Johnson VRO2 Fuel Pump testing & Replacement with OMS

Ok, thanks, I will look at the sync and check all screws, etc. However, I do basic maintenace every season and all looks good under the hood. The carbs were rebuilt at 400 hours and again at 700 hours the other day, all 6 looked good before and after rebuild. When initially checking engine problem, we assumed fuel problem and bypased system with clean tank directly to pump on engine, same problem, so we know its a problem at the motor. Does anyone know of a simple way to say by-pass the sync to see if thats the problem? Also, based on what I have been reading here, a fuel pump cannot be bad or say my problem here because when pumping the bulb it stays nice and hard and has no effect on the engine stalling.

If its not the engine sync, does anyone have any other suggestions I should look at or try, such as engine vacume, etc?

Thanks,
Pete