# VRO Decisions Decisions



## NKlamerus (Jan 4, 2016)

1996 Evinrude 90HP. 

I've been mixing fuel my whole life, all the outboards we own are 2 stroke premix except 1 Merc 150. That's got other issues 

I've got a few leaks now of fuel, Random seals and all the fuel inlet o-rings are leaking. 

Strongly considering disconnecting the VRO pump while im replacing some seals.They are either a godsend or a nightmare but why take the chances? 

I have no problem mixing. The boat is trailered and might be filled on the water twice a year? 

Anyone else locally done this? 

Few pics of leaks


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## sureicanfish (Sep 30, 2007)

Ditch it. One less failure point.


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## oldflathead (Oct 3, 2007)

Yes, as soon as the warranty expires, I disable the VRO.
BTW, VRO is the acronym for Very Rapid Overhaul.
I have a 70 and two 90 John-rudes that were severely damaged when the VRO failed. All three for sale - cheap.

I completed John-rude school in the early 70's and will only own Johnsons or Evinrudes, but I disable the VRO. I have the procedure and will try to post it tonight.


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## NKlamerus (Jan 4, 2016)

Current plan is to remove VRO and replace it with a Fuel Pump and a DIY bracket. http://pages.ebay.com/motors/link/?nav=item.view&id=281953620815&alt=web 

I would leave the VRO assembly on to use the fuel pump off it, but there are so many leaks I'd have to rebuilt it anyway.


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## AndyS (Nov 22, 2011)

I am no professional outboard mechanic ... and have limited shade-tree skills. I've had motors with VRO pumps & those with them removed. My research has informed me of a few things:

* VRO - _Variable_ Ratio Oil (emphasis on the _Variable_) ... what that means is the pump delivers more oil when the motor needs it & less oil when it doesn't (depends on rpm.) Pre-mixing don't necessarily do that so they say.

* The problems you hear about with failing VRO pumps is primarily with motors from a certain time frame ... I forget exactly but sometime mid/late-80's to early-90's? Later years are supposedly far less prone to failure due to design changes.

* If you remove the VRO pump & go to mixing your fuel/oil you are far more likely to foul out plugs if you low-speed & idle a lot as the engine will be getting more oil than required. Oh, and increased carbonization is a possibility also.

Like I said, I'm no pro-mechanic, so anyone feel free to jump in here & correct me if I'm wrong about any of that.

Not sayin' don't do it ... just make sure you put the hammer down & blow her out good every once in awhile when you're out. That's what I do!


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## NKlamerus (Jan 4, 2016)

AndyS said:


> I am no professional outboard mechanic ... and have limited shade-tree skills. I've had motors with VRO pumps & those with them removed. My research has informed me of a few things:
> 
> * VRO - _Variable_ Ratio Oil (emphasis on the _Variable_) ... what that means is the pump delivers more oil when the motor needs it & less oil when it doesn't (depends on rpm.) Pre-mixing don't necessarily do that so they say.
> 
> ...


I've heard this brought up somewhere else as well. I think THT, but I think the variable matches fuel consumption to keep it 50:1. (More fuel at higher rpm, more oil) 

It may increase the ratio at WOT. 

And the last few minutes of all the trips finish with a punch and a freshwater run at the ramp.


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## NKlamerus (Jan 4, 2016)

After talking to my mechanic (best friend from highschool) he definetly recommends removing it. He did on his 40, he's a mech. At Auer marine


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## Splittine (Nov 24, 2007)

If Oldflathead recommends it then do it. He has more experience than everyone on this forum combined.


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## NKlamerus (Jan 4, 2016)

Yeah it's decided. Gonna order the new pump on payday, new fuel lines, new filter, and a fresh tank of gas and oil. 

I don't think I have spark but I can't find out until I get the new pump on, otherwise fuel and oil gets EVERYWHERE


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## Snagged Line (Sep 30, 2007)

Also disconnect the A/C compressor on your truck. They sometimes fail you know...
Sounds like you have already made up your mind on what you want to do and are wanting validation. Of the used boats and motors I ever showed an interest in, I will walk away at the ones that are butchered like you describe.


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## NKlamerus (Jan 4, 2016)

Snagged Line said:


> Also disconnect the A/C compressor on your truck. They sometimes fail you know...
> Sounds like you have already made up your mind on what you want to do and are wanting validation. Of the used boats and motors I ever showed an interest in, I will walk away at the ones that are butchered like you describe.


Technically after I made the post. I messaged my friend after I posted 

The A/C compressor can't be supplemented by a couple minutes at the gas station  

It also doesn't have what seems like 30 rubber failure points.

And a 96 V4 Evinrude with a sunbleached cowl and lower unit isn't appealing anyways lol especially mounted on appealing floating sunturd


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## Splittine (Nov 24, 2007)

Snagged Line said:


> Also disconnect the A/C compressor on your truck. They sometimes fail you know...
> Sounds like you have already made up your mind on what you want to do and are wanting validation. Of the used boats and motors I ever showed an interest in, I will walk away at the ones that are butchered like you describe.


Call me when you walk away and I'll buy it. :whistling:


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## AndyS (Nov 22, 2011)

NKlamerus said:


> I've heard this brought up somewhere else as well. I think THT, .....


Yeah, there were some raging multi-page arguments over there about it when I was reading up on it a few years ago.

I did it on an Evinrude 90 some years back ... didn't notice any difference except seemed like a little bit of a greater tendency to foul plugs once in awhile if I'd been running real low speed all day _(which was par for the course in some of the stumpy lakes I used to fish.)_


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## samm1998 (May 28, 2015)

I went through the same thing with my boat and I think everyone has a unique points for deciding which way to go. 

First, you don't have the VRO system. I'm pretty sure you are actually running the OMS (Oil Management System) version which is much improved from the earlier VRO in many ways. There are several alarms added and your model can even have a system check tachometer that will tell you visually not just audibly what is going on with the motor.

I chose to rehab my OMS system because I have twins and a large fuel tank. Premixing can get a little sketchy in large (75 gallons) quantities. I also like to troll a lot and as someone else mentioned premixing 50:1 protects you on the top end rpm range but is too much on the low end (idling). As a result plugs will get fouled much more frequently.

In your case a smaller motor means smaller gas tank and easier to premix. You also have two fewer plugs to change. If you troll or idle around a lot you should plan on that. The motor will also smoke noticeably more at idle due to essentially doubling up on the oil ratio. The OMS adjust the mix ratio to something like 100:1 at idle. I'm sure there are a few more minor things I am forgetting.

I've used outboards in both configurations and while I like how the motor operates with the OMS system I did like the premix because I KNOW there is oil going to the motor.


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## TheCaptKen (Mar 14, 2011)

You will never hear an educated marine mechanic tell someone to remove the VRO system. A VRO has never ruined a cylinder, dirty carbs does that. If you premix, there is a tendency to add too much oil being the belief that a little is good but more is better. A 2 stroke operates better at 100/1 at low speeds but needs 50/1 at higher speeds thus the reason for VRO. Only those that have little or no understanding of the mechanics of the system will tell you to remove it. They usually have heard to do so by a cousin of a friend that use to own an outboard before he lost his job and had to sell it to support his twelve children. 
I get so tired of this argument.


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## RMS (Dec 9, 2008)

VROs do fail, and it's an expensive one. Been there done that.

OMCs ran quite well on premix for more years than most of us will live before VRO.

Yamaha pioneered oil injection with their two cycle motorcycles in the sixties.
Then they entered the US outboard market in the early 80s with oil injection.
There is an advantage to vary the oil ratio based on RPMs.

OMC and Mercury scrambled to come up with a comparable system.

Mercury did a decent job.

OMC did a lousy job.
It was the beginning of the end for OMC.
The Ficht disaster finished them off for good.

Back in the 50s thru mid 80s the US market had three outboard choices.
If you wanted to haul ass you owned a Merc or a Flying Scott (McCulloch- fifties and early sixties)
If you wanted to get home you owned an OMC.

OMC screwed up big time and compromised their one strength (dependability), and went bankrupt.
Bombardier IMO is still trying to overcome that OMC disaster image to some extent.


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## NKlamerus (Jan 4, 2016)

My decision to replace falls on cost. 

Most the seals are leaking, i can see plastic thats worn and its much cheaper to replace with a fuel pump. Im already disassembling and rebuilding the carbs, new fuel lines, and new filters. 

Now if only i could figure out fuel gallon capacity before trying to fill it all the way up


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## NKlamerus (Jan 4, 2016)

Started pulling VRO off. 

Gonna have to order a new pump, the one i have is a pulse mount, i need a pulse hose fitting.

Not sure if its a V4 Looper, or a Cross flow, not home to check


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## NKlamerus (Jan 4, 2016)

New fuel pump in, they didn't send my freaking seal kit though. So off to order those again and possibly a new vapor seperator assembly


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## NKlamerus (Jan 4, 2016)




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## Sea-r-cy (Oct 3, 2007)

Snagged Line said:


> Also disconnect the A/C compressor on your truck. They sometimes fail you know...


When they do, it doesn't trash the rest of the engine. A failed vro pump does.


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## NKlamerus (Jan 4, 2016)

New pump all settled in 

Anyone know if I just cut the wires to the oil tank for the low oil alarm? And what about the old vro wire plug?


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## X-Shark (Oct 3, 2007)

When OMC fails ..... It fails with NO oil . This is why it's so popular to do away with VRO on them.

When Yamaha fails it full Oil's the motor. That will just cost you a set of spark plugs.

The rest of them..... I don't know?


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## NKlamerus (Jan 4, 2016)

Cranked it for the heck of it, definetly getting fuel as the carbs are pouring at the fuel inlets, as well as out of the air intakes. So far the pump pushes a lot of volume for sure

Not sure if I'm getting spark either, have a tester but need to rig it up 

Starter works great, 3/4 gauges work but the fuel one is out. (Tested ohms at the tank and at the Guage)

Had about a dime size spot of water at the bottom of a Gatorade bottle filled with fuel from the line before I primed the system, gonna installed a water seperator/fuel filter and replace the line from the tank as well. 

Will be at least a week before I can dive back in.


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## AndyS (Nov 22, 2011)

(delete)


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## NKlamerus (Jan 4, 2016)

AndyS said:


> 50:1 =
> 
> 1 gallon oil for 50 gallons of gas
> half-gallon oil for 25 of gas
> ...


I know how to mix the ratio....

I didn't know the capacity of the tank in the boat


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## AndyS (Nov 22, 2011)

NKlamerus said:


> I know how to mix the ratio....
> 
> I didn't know the capacity of the tank in the boat


There should be a plate on top of your tank that tells you how many gallons it holds. The fuel capacity number may be stamped onto the plate. You should be able to see it through one of your access ports. It may be grimy & have to be wiped off to read it.


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## NKlamerus (Jan 4, 2016)

AndyS said:


> There should be a plate on top of your tank that tells you how many gallons it holds. The fuel capacity number may be stamped onto the plate. You should be able to see it through one of your access ports. It may be grimy & have to be wiped off to read it.


That's what I thought but I can't find it, Google was able to help though. I believe it's 24 gallons.


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## NKlamerus (Jan 4, 2016)

https://vimeo.com/197962519 Video Test


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## NKlamerus (Jan 4, 2016)

Running! Little Smokey. New filter and lines did the trick, it's idling and running fine so far 

Lower Shaft seal is leaking though


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## NKlamerus (Jan 4, 2016)

Got the title and registration today! 

Should be on the water for sea trials within the next week


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