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SUBJECT: # 25383: 1989 90 hp Johnson VRO systems

Submitted by Big E ( from TEXAS on 5/11/03 2:06:00 PM

My Mech. is suggesting that I remove my VRO (oil injection)on my motor? He is telling me he has rebuilt several power heads due to the numerous failures with the system. Mine has worked flawlessly over the years. What do ya'll think? BIG E

  1. 5/11/03 5:09:00 PM Submitted by John ( from TEXAS says vro/lower unit
    Big how's the lower unit coming !!!! as far as the vro you know the oil is mixing if you are the think about it the chance of the vro going out on a 89 is better than east bay clearing up before tonight go for it and start mixing ....JOhn

  2. 5/11/03 5:28:00 PM Submitted by Big E ( from TEXAS says Hey John
    The lower unit is coming fine! Have to get with Northshore Marine on Mon. Hope they have a two piece! Anyway when I looked at the drive shaft you could tell at some point I had done the damage my self some time over the years! You could also see that the shaft had been cracked (about the third of they) a long time before it finally broke. Seals were in good shape,and the bearings,gears in good shape too. Power head is solid with good compression! tite lines E

  3. 5/11/03 9:58:00 PM Submitted by Flatfish ( from NORTH CAROLINA says Vro
    I am sure you are aware that the VRO was the last great failure of Johnson. It was the final straw in a long list of engineering problems that finally sent Johnson under before being picked up by Bombardier. Word is now that OMC may be buying the Johnson division back from them. It would serve you well to disconnect the VRO and either premix your fuel or get an autoblender (got one and love it) I've seen way to many fried powerheads on VRO's. If the autoblender fails the fuel stops and keeps from cooking the head. Always carry a extra container of oil and you can tank mix and hook direct from the tank if the autoblender fails (actually never seen one fail!)

  4. 5/11/03 11:58:00 PM Submitted by Nightmare from OHIO says Yeah
    Its possible for a 14 year old component to go out just like any other of that age. First off, you have an alarm system to make you aware of a problem. Second, the propensity is that the fuel side of the vro will go if malfunctioning and the unit overoils. You're more likely to have a power pack or reg/rectifier go out. Its your motor - you can do with it what you want. I've got an '89 also and replaced the vro once due to fuel side going out. Want to take yours off? Send it to me and I'll pay shipping - I don't mind putting a spare in my kit (already got 1 of almost anything else ;).

  5. 5/12/03 7:50:00 AM Submitted by Nick ( from TEXAS says Vro
    Theres a place you can send your vro and get it rebuilt.I think I saw it on this board, do a search and it should come up. I think that if the vro was such a bad design, and caused so many powerhead failures they would have started useing something else don't you?

  6. 5/12/03 9:49:00 AM Submitted by John ( from ILLINOIS says VRO Facts

    VRO stands for Variable Ratio Oiling. On VRO equipped engines built 1989 & prior they oiled approximately 150:1 @ idle and 50:1 @ WOT. On Engines built between 1990 - 1995 they oiled approximately 100:1 @ idle and 50:1 @ WOT. 1996 & newer engines utilize an OMS (Oil Metering System), which looks exactly like the old VRO's and oils at approximately 50:1 at all speeds. Today, it’s still the only system with a “no-oil” delivery warning. Remember that an older engine could have a newer pump - currently all replacement pumps are the OMS version.

    Oil injection is a convenience and I'm not going to say it doesn't fail, but THE most common failure in an OMS or VRO system is in the air motor section of the unit (the fuel side usually gets the credit for this failure). A diaphragm develops a hole (or tear or crack) and the pump stops working. Completely. It doesn't pump fuel or oil - the engine don't run, it don't blow up. Do they fail on the oil section? Yes - but it is VERY rare. More often than not some other problem "blows" the engine. Water in the oil tank or in the fuel system, a plugged main jet in a carb, a blockage in the cooling system, a ring gets caught in a port, severe carbon deposits, the list goes on and on. VRO and OMS get their bad rap from UNEDUCATED, UNTRAINED, APETHETIC “mechanics” and “parts-swappers” who are just too lazy to find the real cause of failure and just point a finger at a pump. If BMC, Merc, Yammie and all the other manufacturers quit making oil injection systems, these guys would freak – THEY WOULDN’T KNOW WHAT TO DO. They would look like fools in front of their customers and bosses…

    The VRO/OMS cannot selectively oil or not oil a cylinder or cylinders. The pump draws fuel and oil from the respective tanks in your boat and mixes them together in an internal chamber of the pump. The mix is then distributed EQUALLY to all cylinders. The next time you hear (or read on the internet) “My engine blew the #3 cylinder, my mechanic said the VRO failed…” – You’ll know not to go to that guys “mechanic”.

    Ok, I feel better now, I'll step down off the soap box.

    The place that rebuilds the pumps is



  7. 5/12/03 10:33:00 AM Submitted by Dunk from NEW JERSEY says Thank You John...
    I guess that needed said again, especially when you have guy's posting that the VRO put OMC out of business. That worse than saying the Ficht problems put OMC out of buisness when it was really Soros shoveling money out the back door claiming he had to keep putting more money into it.

    As far as VRO's on older V4's. Personnally I don't think pouring oil into a tank you can barely get to, making a mess then worrying about if the alarm will work is much of a convenience. And yes the alarms were and are still the most aggravating part of the systems, 98% of the time going off when there is no problem. That is why I disconnect them.

    Here's blow up of a 1994 112hp that has the old style fuel pump. If a VRO needs replaced I convert them back to the old style system. All you need to buy is the fuel pump and the plastic fuel manifold(that vertical pipe in the pic)a few pieces of 5/16" fuel hose. I normally don't even bother with the fuel manifold and use a couple of tee fittings to feed the carbs off the pump. You just have to get the hose pieces long/short enough so the hose's don't kink going into the carbs. Once you do this then you are no longer at Bomb's mercy for buying new OMS's that they don't make rebuild kits for anymore. They do make rebuild kits for the old style pumps...

  8. 5/12/03 11:11:00 AM Submitted by Johnboat ( from TEXAS says Watchful waiting if you decide not to disconnect
    I disconnected my 1984 Johnson 90 several years longer own it but it ran fine for years after the change. My VRO actually failed or partly seemed like a fuel starvation...would not get on plane..even the mechanic took a while to figure it out..miraculously did not hurt the engine. At the very least you should carry some spare oil so that if your engine starts acting up, you can dump the oil in the tank at 50 to 1.

  9. 5/12/03 8:33:00 PM Submitted by Joe ( from MASSACHUSETTS says My brother still has an original VRO
    My brother has a 1984 150 Rude with the original VRO pump on it...he uses it too!

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