Poll: Keep VRO/OMS or Premix?

[Captain Jeff]

Well this is the age old question on the forum but I don't see that anyone has ever done a poll. I have a 1999 Johnson 115. My current VRO/OMS is about 12 years old. I was rebuilding the carbs so I decided to pressure test the OMS and found that the housing leaks a bit at the bottom of the air motor portion. I would gladly buy a rebuild kit but it wouldn't help the housing. I took it apart and after 12 years of seasonal use, the diaphrams were in good condition.

Now I am in a position where I can either buy a new OMS pump or buy a retrofit older style fuel pump and go to pre-mixing the fuel and oil. What are your thoughts? Also how much smoke do you get with pre-mix?

 

[fhhuber]

Main consideration is usually cost and it is usually a little under half the cost to convert to pre-mix when you have to replace a bad VRO pump.

When VRO works, it works great.
When it fails, it can take out the whole power head.
A new VRO pump should be reliable for many years. ($450 when I checked a couple of years ago.) You do have to remember to put oil in the oil tank.
Pre-mix works every time you remember to put oil in the gas.
The pumps to convert were appx $90 each and I needed 2 for my 150.

 

[jimmbo]

Interesting, I voted to keep the OMS and it says no votes for that.

 

[Scott Danforth]

I say keep it. its less than half a BOAT unit to fix it right

 

[flyingscott]

Keep it. That is a good system that is very reliable. Your poll does not seem to take yes votes.

 

[dingbat]

Pre-mix works every time you remember to put oil in the gas.

I vote replace and keep.....

My low oil alarms goes off if I forget to refill the 3 gallon oil tank.

if you forget to put oil in the tank.....the alarm goes boom.....

 

[Tony T.]

My 1992 60 hp Evinrude had the VRO when I bought the boat and motor back in 2015 but it had already been dis-connected by original owner. I have no idea if it just quit working right or if the original owner just decided to dis-connect and pre-mix for piece of mind. I've been pre-mixing for years and have no problem doing that myself.

Tony

 

[flyingscott]

In all honesty just as many if not more engines, have been wrecked by people forgetting to mix the gas and oil than there have been destroyed by oil injection failures.

 

[cfauvel]

the poll code is jacked up....not allowing YES votes...

From what I know of the VRO internally (I now know the internals pretty well) there is very little chance that the oil piston inside won't pump oil...the piston is directly connected to the fuel pump which is connected to the air motor.

There IS a chance, ( I have someone on the forum who is experiencing that condition, and forensics in the future will allow me to know exactly the issue).

in my case my faulty VRO was pumping TOO much oil...that pump is from 1999. Before that, the pump wasn't pumping fuel....so motor wasn't running...if it isn't running it isn't denied oil.

I've come to the middle....being a VRO/OMS fan, knowing the part intimately I trust it....but I totally can see how peace of mind could be given by pre-mixing.. The new OMS price (I've seen it as low as $380) which makes it a hard sell when two regular pumps in series would be about $200..

too bad the poll isn't working right.

 

[Captain Jeff]

Hey guys, thanks for the input. Great info. I tried to fix the poll but it isn't working. I think it is the "/" between VRO and OMS that is making the server have issues. Maybe a moderator can step in and fix it?

 

[Chris1956]

Repeal and Replace...Naturally!

Err make that repair and replace....

 

[gm280]

I have never owns a Variable Ratio Oiler system. But it must have been a great idea to offer the best running conditions when they initially developed the system. And, yes, I have read where some has changed they VRO's over to premix. If I ever buy an engine with VRO, I will go through it with a fine tooth comb and repair/replace any iffy or defective part and try it. I am finicky to make things work like they were new. JMHO

 

[Sirrobin53]

My 94 150 Evinrude got to leaking in the OMS in 2007. Like almost everyone else here on the forum I was grieving over $400 for a new system. However, the answer for me was clear. If the original could last that long with no problems I will put another one back on without hesitation. I find adding to the oil tank much easier than having to fool with a funnel and spill oil all over everywhere in the process of getting it to the fuel tank. Bet you can't guess how I vote?

 

[ahicks]

I think it depends on the age/condition of the engine. On older stuff, common sense would tell you that rubber components are more likely to fail, and spending a lot of money on a 20+ year old engine may not be the wisest move.

So from a practical standpoint, I'm less likely going to want to replace/rebuild a VRO system on an old beat up 40 or 50 horse that's got hundreds and hundreds of hours on it, but a low time 85+ horse engine that been been garage stored and used 3 times a season may be worth it.