To VRO or Not

[rickdb1boat]

Hi All, I posted before trying to find out how to disable my VRO on a 1991 Evinrude 70HP & got the info I needed to do it! My question now is: What are your opinions on doing this? Are these systems that unreliable on OMC products? I read somewhere in the posts the the #2 CYL is prone to problems and that there is some kind of fix for this, but not sure what it is! Would premixing my own cut down on the chances of having a problem with the #2 CYL, or for that matter, the whole motor? I just had this engine rebuilt last year and don't want any problems if I can avoid it. Any input would be appreciated, Thanks, Rick

 

[DJ]

Re: To VRO or Not

Rick,<br /><br />I am a believer in the system. The system does require some maintenance however. Many failures were blamed on the VRO system that had nothing to do with it. And, few people maintain these systems. Here is what I used to do every year when I owned one.<br /><br />1. Remove the oil tank and thoroughly clean. <br /><br />2. Get rid of the old oil.<br /><br />3. Replace the pick up filter.<br /><br />4. Inspect all lines and repair/replace as necessary.<br /><br />5. Re prime system and run pre mix until I could verify oil useage.<br /><br />6. Make sure the warning horn is working.<br /><br />The failure you described (losing #2) is not a symptom of a failed VRO. VRO CANNOT discriminate between cylinders. That is one untruth that was/is widely believed. It mixes oil with the fuel BEFORE it gets to the carbs. A scored cylinder is indicative of a clogged carb. jet or other malodies such as excess carbon build up or ring breakage.

 

[tazatax]

Re: To VRO or Not

Rick,<br /> I have a '87 140 rude it ran great until somehow h2o got into the oil resevoir.(never looked milky) anyhow after a $1300 rebuild my mechanic and i decided to do away with the VRO and now i pre-mix. Iwas told not to trust the VRO but i gave it the benefit and ..........it bit me!

 

[DJ]

Re: To VRO or Not

Rick and Tazatax,<br /><br />Yep, water can be a problem in VRO tanks. It WILL NOT look milky because there is nothing in there to mix it up. Water is heavier than oil, thus it sits at the bottom of the tank. Not like a gearcase. Maintenance would have prevented this. Not unlike filling your car crankcase with water and wondering why the engine blew up.<br /><br />The VRO system did not cause the engine to fail, water did. You would have failed it also with water in your fuel tank.

 

[clanton]

Re: To VRO or Not

If dealer rebuildt the engine, you should ask him if these Service Bulletins were check or installed during rebuild.<br /><br />SB2221 Temp sensor dated Feb 1990<br />SB2225 Thermostat seat dated April 1990<br />SB2271 Calibration change, carb jets and timing<br /> kit pn 436677<br />SB2276R1 Relocated tattle tale nipple on block<br /> dated Mar 1993<br />Waterpump Kit pn 432955 included SB2276R1 and <br /> different pressure relief spring.

 

[rickdb1boat]

Re: To VRO or Not

Thanks for the replys guys! I'm kinda torn between disconnecting it at such an early stage in the game, since it was just rebuilt, with all new VRO parts installed at the same time. I just don't want to do the wrong thing and have it blow up. I have always had engines where I mixed my own and never cooked a motor! Just trying to decide if this system is reliable enough not to have to worry about it. From what I understand, by the time you get a warning, other than low oil in the tank, it's too late! That kinda scares me a bit! To bad they don't make them so that they either shut down or at least go into a slow mode when the pump fails. What to do, What to do! Rick

 

[JB]

Re: To VRO or Not

Hi, Rick.<br /><br />DJohns is correct. Very few failures are caused by the VRO system and most of those are the result of maintenance failures.<br /><br />However. Zero failures are caused by properly mixed premix, maintenance or otherwise (unless, of course, you have a brain seizure and don't put any oil in the tank).<br /><br />I am elderly. I fish alone a lot, in the most remote places I can find. I believe in fail-safe operation if at all possible. That means premixed fuel for a 2 stroke with carbs. I believe that the odds are more in my favor that way.<br /><br />All that said, I now use a 4 stroke because it works better than a 2 stroke, makes less noise, no smoke, etc.,etc. I'm sure you've heard all about how wondewrful we 4 stroke users think our engines are.<br /><br />But I digress. I disconnect oil injection systems to improve my odds of getting home.

 

[Terry H]

Re: To VRO or Not

I disconnected the vro on my motor just to simplify. I put a new vro pump on when I got the motor but never ran it. Primix from the start. I don't have an extra line to kink, or oil tank to check, or oil tank to get water in. I don't recommend vro or premix 'cause they both work, I premix the fuel so there's one less mechanical system to deal with...just a Thought

 

[Philby]

Re: To VRO or Not

I'm with Djohn on this.<br /><br />If you are running a vro you have to keep your eye on it.<br /><br />I:<br /><br />1/ Change the oil and clean the tank at the start of every season. It is amazing haow water can get into these things.<br /><br />2/ Take of the hose at the pump where the oil see through tube is and punp fresh oil through just to purge the lines.<br /><br />3/ Check every trip that there is oil in the see through.<br /><br />4/ Make sure your horn is working. If it isn't, don't chance it.

 

[Kiwi]

Re: To VRO or Not

oh gawd ! just when I was starting to feel comfortable about the oil injection on my Suzuki

 

[rickdb1boat]

Re: To VRO or Not

Thanks for the opinions guys but a few more comments and questions and I'll let it go!<br /><br />I know that the "Low Oil" warning works, because I have been low enough once, where the horn did sound at the 20 second interval. Are there any other warning that should sound that would protect the motor before destruction? I believe from looking at the Clymer manual that it will sound every 2 seconds if the pump is not getting oil at all(AKA Kinked Line, ECT), but will the motor be dead by then or if I shut it off right away, can I save it? The manual also says that I can still mix a 50:1 with this VRO system if I want. Is the VRO smart enough to determine the oil ratio if I pre-mix along with having the VRO hooked up? I find that hard to beleive! Seems like it would be running very rich on the oil side if I did that! I know when I first got the motor back, they had me run it for the first 10 HRS with 50:1 in the gas tank, along with the VRO running, too. That was to be sure that the VRO was working properly and I really did'nt notice an over abundance of smoke or anything during that break-in time, although I was putting oil in the tank and the VRo also. Seems like that would be a waste of oil to do both! I am mainly concerned that the 2 sec. warning will save my engine as it supposed to do! If not, goodbye VRO!! Once again, Thanks and any other thoughts are appreciated! Rick (PS- How do I make sure the 2 sec warning is working correctly?)

 

[rickdb1boat]

Re: To VRO or Not

bump

 

[clanton]

Re: To VRO or Not

When you do the 50/1 mix thing in fuel tank, you disconnect the oil hose to pump and cap pump and line. side of VRO pump, instructions used to be in owner manuals. The 2 second beeping warning will only save the engine if you shut the engine down.

 

[DJ]

Re: To VRO or Not

Rick,<br /><br />You are correct, the VRO system does not know that you have pre-mix in the tank. The dealer told you to run pre-mix during break in for two reasons.<br /><br />1. Running "double oil" is standard operating procedure for breaking in new engines.<br /><br />2. Making sure the VRO is working.<br /><br />The easiest way to tell it is working is to fill the tank up and mark a line on the side of it. Then check after an outing.<br /><br />Your warning horn tells you that you have:<br /><br />1. Low oil. Just like a low fuel indicator in a car. You're not out of oil, just low.<br /><br />2. VRO pump not working. That is the one that you will have to shut the engine down immediately. You can always dump oil in the fuel and make it home. The newer VRO systems did employ a feature called: S L O W. This system did cut back engine RPM for no oil or overheat conditions. These SLOW systems are nothing new to big diesels. In those engines it's called "derate".

 

[rickdb1boat]

Re: To VRO or Not

Thanks djohns19, That was the answer I was after! So as long as I shut down immediatly after I hear the warning, I should be OK, providing the horn goes off like it's supposed to. Does anyone know how I can check the "No oil to Pump Warning" warning horn?(2 Sec. Horn interval Warning) Either on or off the water, just so I know it's working! Rick

 

[seahorse5]

Re: To VRO or Not

The VRO does not put the motor into the SLOW mode, only an overheat does.<br /><br />If there is a lack of oil pumping pressure, the alarm sounds the on and off tone, but the motor stays at the same rpm until the operator moves the throttle back or the engine dies.<br /><br />The VRO was last used in 1992. The next year it became the OMS, oil metering system, that only varied the mix from 75:1 at idle to 50:1 at WOT. They called it 60:1 as an average.<br /><br />Bass and Walleye Boats did a who.e story on VRO and troubleshooting a couple of years ago. Trailer Boats also carried the article.

 

[rickdb1boat]

Re: To VRO or Not

If I disconnected the oil line to the Pump and plugged it at the Pump, and mixed a 50:1 mixture in the tank to be sure it's lubricated, Left all the wiring connected and ran it, would that make the "No Oil Pressure At the Pump Warning" Sound? Just a thought to see if it really works! Rick

 

[seahorse5]

Re: To VRO or Not

That is how you test the no-oil system. Make sure the 50:1 mix has been run for a while before you disconnect the VRO. Test your horn first to make sure it works by grounding one of the tan temp sensor wires while the key is ON.<br /><br />After you cap off the oil fitting, you have to run the engine a while before the horn sounds. Since you are burning a small amount of fuel and only 2% oil, it takes a while to use up the residual oil in the VRO before the alarm beeps at you.