why disconnect the vro ?

hookinfinger · Aug 16, 2003

Hello everyone, I recently purchased a 1990 15' Boston Whaler with 1990 Johnson 70hp vro engine. The previous owner had disconneted the vro. In reading several posts on this site,I noticed many people have mentioned that they have disconneted their vro also. Why do people disconnet ? Did Johnson make a mistake by adding the vro system to their engines in the first place ? Could you give my an overview of the systems purpose ? I have ordered the original owners, parts and service manuals and hope to have them on hand soon. I will not be working on my engine, but I would like to learn how they work. Maybe they will also help me use better termonology should I post future topics. Thank You for time, Dennis

Solittle · Aug 16, 2003

Re: why disconnect the vro ?

Dennis - That is a great combo that you have - - Oh and welcome. I assume that you know the intent of the VRO is to mix the oil with the fuel at the engine and to vary the oil to fuel mix in proportion to the rpm and needs of the motor. When working properly it does this well and helps cut down the amount of oil released into the air and water. The reason many, including myself, have eliminated the VRO is that if it fails while you are running hard you have lost an engine. Not only is your day ruined but you will have to turn your wallet upside down and shake vigerously to get you motor fixed. In my view the VRO is a well intentioned feature that adds more complexity to motors that are already complex. Pre mix does not fail unless you forget to add the oil in the correct amount. To carry it one (or many) steps further the designors of todays engines have added scads of sensors and boxes of computers. To diagnose a problem you have to have racks of test equipment and technicians trained on how to use them. Look at this board at all the posts submitted by guys who are keeping their 20, 30 and 40 year plus motors going. In 20, 30 and 40 years from now how many of todays motors will still be running? Yeah technology is great and done a lot of things to make aour lives easier. But there is a cost that goes along with it. For example I got a quote recently of 14 grand to repower my boat. 14 GRAND!!!! and that is with a single low tech 2 cycle 200. I won't encourage you to yank your VRO. As for me were I to buy a motor today with VRO I would take it off as part of my first service.

zzzzz · Aug 16, 2003

Re: why disconnect the vro ?

also,due to a high incidence of failure-it has earned the nickname "Very Rarely Oils"

walleyehed · Aug 16, 2003

Re: why disconnect the vro ?

Reason to delete or bypass VRO; PIECE OF MIND !!!

hookinfinger · Aug 16, 2003

Re: why disconnect the vro ?

Thanks for all the replys. SoLittle, I read you loud and clear on the potential of engine failure and the subsequent wallet failure. After reading your replys I am convinced that the " VRO has got to go". Regards, Dennis

Dhadley · Aug 16, 2003

Re: why disconnect the vro ?

All mine work fine. Wouldn't have it any other way. Thanks for asking!

walleyehed · Aug 16, 2003

Re: why disconnect the vro ?

There are those that "HAVE", and those that "WILL"..............

walleyehed · Aug 16, 2003

Re: why disconnect the vro ?

I kinda feel like maybe you're calling me a dumb a_s by adding the sarcastic comments, and I guess i will shake it off, but OMC got rid of the VRO1 pumps because they were a failure waiting to happen...the 100:1 idle/50:1 WOT., and went with a very simple version, the VROII, 50:1 all the time. The new pumps are much more reliable, but still fail occasionaly. Most OMC/Bombardier dealers will tell you if you have an early VRO pump go out, it is best to install a regular fuel pump and plug-off the rest of the oil system & premix. I see the 30+ yrs with OMC listed once in awhile, and my father & I are 27 yrs. with OMC, and now Bombardier, and I don't see how a few engines that work, make the other opinions or observations null-N-void.......

Dhadley · Aug 17, 2003

Re: why disconnect the vro ?

To be honest, yes some pumps have failed. Most of those quit pumping fuel so the motor quits or just doesnt run right. No damage to the powerhead. On the other hand we have seen hundreds of motors with damage that was blamed on the oil pump. Regardless of the pumping ratio. Most had something wrong with one or two cylinders and the others were perfect. The E/J oil injection system cannot pick on one cylinder (some other brands can). Lots of powerheads were damaged because there was water in the oil tank. Thats not an oil pumps fault. It was pumping whatever the captian had in there. Weve seen damage because the oil tank was dry (yes, the alarm worked -- go figure). Thats not the pumps fault either. The pumps can actually sense a fuel restriction (possibly resulting in a lean condition) and provide extra oil for protection. With that particular model motor I would be more concerned about making sure the updates were all done and address the lean condition in the mid range they tend to have. Good luck!

hookinfinger · Aug 17, 2003

Re: why disconnect the vro ?

Well Dhadley, I can tell you after reading your closeing remarks, I AM now more concerned about updates and lean conditions. Could you please expound on those issues when you have time ? Thank You, Dennis

Dhadley · Aug 17, 2003

Re: why disconnect the vro ?

Mr Clanton has all the exact updates, as will any good Evinrude / Johnson dealer in your area, but they include relocating the fitting for the overboard "tattletail", some rejetting (hi speed) and an impeller change (away from the 3 blade and back to the old 6 blade). We have found that going richer slightly on the mid range jets helps the cruising range and longevity. Make sure you stick with Champion plugs and fresh 87 octane fuel with good oil.

clanton · Aug 17, 2003

Re: why disconnect the vro ?

I have a 15 ft whaler, with same engine 1992, have only run in test tank so far( too many other projects). There are 5/6 service bulletins for this engine. Try search for bulletins. One bulletin has a jet and timing change. I had VRO pump rebuildt by DFI, and I plan on running some oil in tank. SB 2221 Temp sensor new sensor pn 584166, tan/blue stripe wire. SB 2225 thermostat seat new seat pn 336416, may not need this in fresh water. SB 2271 jet and timing kit pn 435911. SB 2276R1 relocate tattle tale nipple to top of block. SB 2276R1 and new pressure relief springs comes in waterpump kit pn 432955. Thermostat was a production change for most all OMC engines, just a letter and pn change. I think the new style was black and the old style white.

hookinfinger · Aug 17, 2003

Re: why disconnect the vro ?

Thanks Dhadley and Clanton for the information. I have an appointment with the local Whaler dealer this coming Tuesday. I will print out the information that you have given and bring it with me. Regards, Dennis

billfishfla · Aug 17, 2003

Re: why disconnect the vro ?

walleyehed Are you saying that it is necessary to install a new fuel pump if you disconmnect the VRO I disconnected my VRO On a 70 hp Johnson ( 2000 ) after IT FAILED AND WAS TOLD IT HAD A HOLE IN THE DIAPHRAM ??????????????????? BUT never was told by the techs at Johnson to put in a different Fuel Pump wazzzzz == up ???/

walleyehed · Aug 17, 2003

Re: why disconnect the vro ?

It is dependant on the particular pump failure...there are alot of people out there running with the VRO pump and just premixing oil in the fuel. You must disconnect the low-oil/no-oil leads and cap the port to the pump. The only reason I went back to a std. style fuel pump is to get the mass of crap out of the way....you'll be just fine. There just happens to be more than one way to skin a cat, so to speak.......

why disconnect the vro ?

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