posted 05-31-2005 08:09 PM ET (US)            

If made for extra space on deck, I don't have to prime oil tank bulbs or monitor consumption, worry about cracked or leaking tanks, lines, or pump.

posted 06-01-2005 10:12 AM ET (US)            

Frankly, regardless of the unit's efficacy, the space savings in such a small boat made it well worth the effort.

posted 06-02-2005 07:41 AM ET (US)            

http://continuouswave.com/whaler/reference/VRO.html

Depending on what type of failure inside the motor occured, you might have a different opinion of the person who diagnosed "a bad VRO".

posted 06-02-2005 09:11 AM ET (US)            

On my current engine, a 1992 Evinrude 225-HP, the VRO system is intact and working. I upgraded the engine to have the SystemCheck gauge system. The engine has several alarms and sensors which monitor the operation of the VRO. They check for:

--oil level in the reservoir
--oil flow from the mixing pump in proper proportion to engine speed
--flow restriction in the fuel line

Pre-mixing of fuel and oil would be inconvenient for me. Because the boat is kept of a trailer, most of the fuel I buy is on the highway. The tank holds 77-gallons. I typically buy over 50 gallons when adding fuel. The fuel fill is on the side of the cabin, and, when the boat is on the trailer, it is over my head. It is very awkward to reach the fuel fill when either standing on the pavement or standing in the cockpit. (it is very handy dockside, however.) It would take two people and a ladder to properly pre-mix the gasoline and oil using the recommended technique. (The recommended technique is to use a very wide mouth funnel and to pour the oil and gasoline into the funnel simultaneously, mixing them as they enter the tank.) When filling a large tank like this you have to guess about the exact amount of fuel to be added. The amount of oil to be mixed then has to be computed based on this guess.

It is far more convenient to just top off both the fuel tank and the oil tank. These are in good proportion, too. The oil tank holds 1.8-gallons. This generally means I can pour in a gallon of oil at a time when fueling. If I have a full tank of gasoline, say 70-gallons, I will need 70/50 = 1.4 gallons of oil. Thus if the oil tank is close to full, I know I have enough oil in the reservoir to run the boat until the fuel tank is empty. Re-fueling becomes a simple process of just topping off both tanks.

For boats with smaller tank capacities and with the fuel fill in a more convenient location, pre-mixing may be less of a chore.

When pre-mixing, the volume of gasoline added is often constrained in increments that are proportional to the amount of oil in a handy container size. That is typically a quart. So gasoline is added in proportionate amounts, which would be twelve gallons (at roughly 50:1 mixing). What generally happens is the tank is not filled to capacity, or some extra oil gets thrown in to empty a quart can.

The math can get a little more challenging if you happen to buy fuel overseas. This includes Canada, where I do much of my boating. The pump often dispenses fuel in liters. Or sometimes in Imperial Gallons (which have 5-quarts to a gallon).

It is my experience that if pre-mixing in a small tank the ratio of oil to fuel will tend to increase over time due to errors in adding oil. The tendency is to err on the side of too much oil. We used to have this situation on a small auxiliary motor on a sailboat. About three months into the season the fuel in the tank had so much oil in it that the engine could barely run!

Another problem with pre-mixing is the tendency to buy the oil in smaller containers so they are more convenient to use. Buying oil in quart or pint packaging is more expensive. I buy oil only in gallon containers. (By the way, I buy it from my dealer's bulk oil tank and re-use the containers.)

posted 06-02-2005 03:46 PM ET (US)            

As jimh mentioned, it is very difficult to get the correct amount of oil mixed with the fuel for many reasons.

Yes, if you put in 6.25 gallons of fuel in at a time then you can add the correct amount, but how many times when you FILL up the tank does the amount of fuel equal, 6.25, 12.5, 18.75, etc. gallons.

50:1 Ratio
50 gallons of fuel to 1 gallon of oil
25 gallons of fuel to 2 quarts of oil
12.5 gallons of fuel to 1 quart of oil
6.25 gallons of fuel to 1 pint of oil.

I used to mix my fuel/oil back in the 70's when I had my 13' Sport with an Evinrude 35hp on it. Ended up always adding a little more oil just to be on the safe side. Also had to carry one of those professional style measuring containers with the ounces marked on the side. Messy... Now what do you do with this container.

I owned a 1985 Evinrude 70hp for 15 years... Never had to do anything but replace a ratchet clamp on the oil hose througout the years. That's about all the maintenance I can think of unless the bulb or hose starts to go bad from being out in the weather.

Not everyone's boating needs are the same. We all have to look at the big picture. Some people take extended trips and either need to carry extra oil onboard or find a dock station that sells pre-mix. Pre-mix isn't cheap.

Another thing about pre-mix, is you are always running rich at idle. No if's, and's, or but's about it. The VRO system uses less oil at lower RPM's. More along the lines of 75:1 to 80:1. Running rich has a tendency to foul spark plugs.

I now own a 1985 Evinrude 150 hp and I fill up the oil tank before I take it out. No matter what, I always carry 2 quarts of extra oil in the boat. For extended vacations, I will take either a 1 gallon or 2 1/2 gallon container of OMC oil with me and keep it at the Cabin, Motel, etc...

I buy my oil in bulk like jimh does. I have 2 of the factory 2 1/2 gallon containers that my dealer fills up from his 50 gallon drum. Every little bit of savings helps.

So, I save a little money on the cost of oil by buying it in bulk. I save a little money on the amount of oil used because the VRO meters the oil according to RPM's. I also save a little money on plugs because they do not get fouled as frequently by running too rich from pre-mix. Again, every little bit of savings helps. I can buy more fuel with the savings.

The 4 strokes do have the advantage of not having to carry oil onboard and the space necessary for the oil tank.

I personally would never consider disconnecting my VRO system.

posted 06-02-2005 04:14 PM ET (US)            

PSSST, over here buddy, closer, closer, ok

2.5 ounces oil per 1 gallon gasoline

Write it back'erds and tape it to your forehead
if you have problems remembering, then look in a mirror.

posted 06-02-2005 05:48 PM ET (US)            

Don't forget to help us to convert this to liters.
And Imperial Gallons..

Please...

I also have a problem when calculating the oil when I buy 37.73 gallons of gasoline.

I think I will buy a slide rule or electronic calcualtor and carry it when I go boating. :-)

I was always good in math but I think I have a mental block when it comes to adding the right amount oil... Just can't stand it I guess... I just want to go boating.

I guess the guy who designed the VRO system couldn't stand figuring out the amount of oil to add to his tank either... :-)

I'm not picking on you prj, it just seemed funny that someone would say something like that.

That would be like me saying to someone, (no one particular)
If you can't fix or work on your own computer, then you shouldn't own a computer! I guess you could say that about many things...

posted 06-02-2005 09:23 PM ET (US)            

The main reason it doesn't phase me to pre-mix on my 15' Sport is because I have two 6 gallon tanks. (easy portability, easy pre-mix measurements).

As for VRO maintenance, http://continuouswave.com/whaler/reference/VRO.html

Space for the tank was not an issue on the Rage, so after reconstructing the VRO pump, I filled the tank with oil, and have been happy ever since I burned the last pre-mix out of the fuel tank at the end of break-in.

posted 06-02-2005 10:34 PM ET (US)            

Is "VRO" an OMC-specific term, and therefore inappropriate for my Suzukis?

posted 06-02-2005 10:50 PM ET (US)            

Basic components of the system are a tank, line with primer and pump that connects to some sort of port on the motor. Seems easy enough for people to disable them, should be pretty easy to reconnect. Chances are that everything you need may still be there.

I just went through a rebuild of my 1989 150. The VRO had nothing to do with it. That motor had alot of hours on it with the original VRO.

I think that some of the mechanics may want you to disconnect the VRO as a form of insurance for themselves. Disconnect the VRO, go to premixed, and it's hard to blame them for a problem. If I were a mechanic I'd probably want the same thing.

posted 06-03-2005 09:41 AM ET (US)            

VRO²®

On Yamaha engines the variable rate oiling is called PRECISION BLEND.

Mercury outboards have this feature, but I could not find any specific mention of it by a special name. In the specifications they just refer to it as "single point variable ratio oil injection" or sometimes as "electronic single point variable ratio oil injection."

I don't know how Honda, Suzuki, Nissan, Tohatsu, or others refer to this feature.

My impression is that these variable ratio oiling systems on outboards other than OMC-brands are seldom if ever disconnected. I cannot recall hearing a even a single report of someone disconnecting it from a Yamaha or Mercury.

The use of crankcase vacuum pulses to operate the OMC VRO pump is often mentioned as a problem, and some other systems apparently use different techniques for driving the oil injection. On a Mercury--at least on some models--it is apparently driven electronically, or so I would assume from the nomenclature.

posted 06-03-2005 11:47 AM ET (US)         

Again, because OMC entered the market first (at least on a large scale), they apparently had some initial problems with their system. Personally, I have never come across a problem with mine or anyone else's. Often, mechanics misdiagnose a problem and look to blame a new technology because it's easier than figuring out the real reason (or they're incapable of determining the real problem). They perpetuate this in discussions with customers and the myth begins.

posted 06-03-2005 12:10 PM ET (US)            

I agree with JimH - generally, for larger boats/outboards, pre-mixing your fuel/oil is a royal pain for all the reasons mentioned above. On the smaller boats, it is much easier to mix (portable tanks) and frees up valuable space aboard for storage, deck space, etc.

I would NOT want to pre-mix the fuel for my 18' Outrage, although I know a fellow forum member does with his. Important to note, however, is that that forum member doesn't use this boat very often anymore in favor of a vessel with "oil injection". Might this convenience factor have some contributing effect on this phenomenon? Who kows...it would for me.

posted 06-03-2005 12:24 PM ET (US)            

JimH: I don't think Honda called their VRO anything, I thought they were always 4-stroke and required no mixing.

posted 06-04-2005 02:52 PM ET (US)         

When OMC collapsed, there many were newspaper and boat mag articles, besides web based stuff, about why. Besides Ficht, VRO was often mentioned. An OMC engineer, I'm sure disgruntled, said that the system was a poor design from day one, as evidenced by the need for continuous upgrades, improvements and warning system upgrades. He said rather than spend the money to redesign it, they just put more alarms on it so people would know when it was failing. Mercury and Yamaha have never had do to a thing to their designs, both bulletproof. He said that OMC made continuously bad corporate decisions not to COMPLETELY re-design the system, rather than bandaging it.

Another article I remember reading was that in the late 80's models, where most of the serious engine failures occured, supposedly as a result of VRO, OMC replaced over 4000 powerheads under warranty.

And look what we see here continuously. Endless OMC engines with oil injection disconnected, for fear of failure. You just don't see that with Yamaha or Mercury, unless an OMC friend of mechanic recommended they do it!!

posted 06-04-2005 11:40 PM ET (US)            

It is true that early VRO systems like the one on my 1985 70Hp Johnson had no electronic warning systems other than low oil in the reservoir tank. However, the 1995 VRO system I last dismantled has a brain and can sense when the pulses on the oil side of the fuel pump are not in line with the RPM's of the engine.

As for smoke at startup, that's a sign I want to see! All those parts that were just sitting stone cold are now moving, and knowing they are properly lubricated is something that is important. This isn't a 4-stroke automobile we're driving here, where smoke at startup is a nasty bad thing that means your valve guide seals are shot.

posted 06-06-2005 11:30 PM ET (US)            

All the comments, info, etc. posted here about VRO's are very informative, however, it still doesn't do alot to ease my mind about VRO.

Yesterdays maiden voyage of the season found the alarm going off for the 1st time for me. We had just left the dock and were moving at about 7 knots, not even planing, when the alarm went off with a continuous beep. I put the boat in neutral and it stayed on for about five minutes then went silent as suddenly as it came on.

My passenger was freaked out by the alarm and didn't feel comfortable continuing even though the alarm was no longer blaring so we turned back (and proceeded to kill the prop on a submerged rock, I swear if I didn't have poor luck lately I wouldn't have any luck at all).

When I returned to the dock I checked the oil tank, line, etc. as best as I could but there didn't appear to be any leaks, etc. From what I gather here the long continuous tone is over heat. How does a water cooled engine over heat? On a car it's easy to diagnose but on an engine what are the signs?

The previous owner told me to pre-mix 100:1 even with the VRO working, just in case. It sounds good but I'm afraid the engine is getting too much oil as it's very oily on the transom.

posted 06-06-2005 11:59 PM ET (US)            

I figured if I was premixing anyway and had all these other nagging doubts, why not disconnect, premix anyway, and not worry about it?

By disconnecting I have eliminated many concerns and added no extra effort. Some may argue that I'm using more oil than I need to at certain speeds, but I'm still only using 50:1 no matter what. Not 100:1 PLUS whatever the VRO pumped the way it was before.

posted 06-07-2005 08:16 AM ET (US)            

You asked about proper maintenance of VRO. Periodically check under Cowling, run motor without cowling and check connections or dry rotted hoses/fuel lines etc... After years of use, a sludge may build up at the bottom of the oil tank. This may cause a blockage in the pick up hose. Its a good idea to empty oil tank every few seasons and check for debris.

If you keep your boat on a trailer at your home, Start it up every week or so. It keeps fluids/lubrication moving and you will see the blue exhaust smoke and know the VRO is working. Im not a mechanic but, these motors are reliable due to their simplicity and they have a great reputation. That being said, they also require basic maintenance. DE-CARB every year, Replace-plugs every year, fuel filters every year, lower gear lube every year, water pumps and thermostats every 2 years......

posted 06-07-2005 08:24 AM ET (US)            

As far as I recall the stream was coming out fine but in all honesty I don't think I was checking when the alarm was sounding (I was spending my time trying to reassure my passenger that we weren't sinking). When we got back to the marina I washed the engine and the stream was fine so maybe it was something blocking the intakes momentarily. Am I safe to assume that if no water is coming out of the engine it's overheating? And if the stream is coming out fine then it's not overheating?

I don't have an opinion either way regarding the VRO, I do not know enough about it and, not being particularly gifted mechanically, probably never will. I think I would lean towards disconnecting it for two reasons, as efduffer said I am already pre-mixing and have no issue with the science of ratios also I would feel more at ease knowing that the oil was there because I put it there (it's along the same lines as packing my own parachute).

Once I replace the prop I will have another go with it (sans passenger). Speaking of props are there any recommendations?

posted 06-07-2005 09:49 AM ET (US)            

"fine" in regards to the water stream telltale is far too subjective.

If you are not absolutely certain that the water pump / impeller
has been changed in the last 2 years, DO SO NOW.

posted 06-07-2005 11:47 AM ET (US)            

Some members seem a bit defensive when it comes to the VRO and lack of knowledge regarding it. Please bear in mind that many, like myself, bought used and most did not come with an owner’s manual. And please accept my apologies for making excuses based on gender, but when my mind was young and much more absorbent I had to sit through sewing and cooking (Home Economics) whilst the boys got to learn small engine repair and woodworking. I'm starting at almost 50 years old to just get a base knowledge of all things mechanical (I can, however, make a hell of a meatloaf or fashion a lovely frock out of your old curtains!).

posted 06-07-2005 12:50 PM ET (US)            

Changing the impeller is more of a regular maintenance project than part of a rebuild.

You can get an owner's manual for your motor. You can also get the OEM service manual. Reading these materials will increase your confidence about using and caring for your motor.

Start by posting a "wanted to buy" post in the marketplace area here. Someone may have one available. Be sure to include your motor's year, make, model, and any serial number information you can find on the motor.

If you don't find one among the membership here, you can order one. I recently ordered the service manual for a 1973 Johnson 65 hp. Ken Cook (do a Google search) is one source. Other members may have better ideas for where to look for one.

If you're completely new to boating, as I am, I'd also recommend buying a copy of Powerboating: A Woman's Guide by Sandy Lindsey.

posted 06-07-2005 01:55 PM ET (US)            

There are two connections on your engine that are connected to the warning horn system.

1. The VRO tank
2. The Overheat sensor

You can check that these are working via the article in the reference section on VRO that where2 mentions above.

A Simple Test when your alarm sounds:

1. Disconnect the Overheat sensor via the Knife Terminal connector, if the alarm stops, then you are either overheating or your sensor is bad.

2. Disconnect the VRO wire from the tank via the Knife Terminal connector. If the alarm stops, then you have a short somewhere in the VRO tank sending unit. This could be an intermittent short so sometimes the horn might sound and sometimes it doesn't.

Here are the sounds that should be normal for the alarm system for your motor.
1. Constant ON.... Overheat problem
2. Sound every 20 seconds.... Low Oil
3. Sound every 1/2 second and off for 1/2 second... No Oil

Those are the normal sounds, but as I mentioned above, you still could be getting a Constant sound if the VRO sending unit is grounding itself out internally. I had this happen to me. When I disconnected the VRO (Tan wire) knife connection, the constant alarm stopped. The VRO tank does not have a constant alarm so I knew something was wrong inside the tank. I replaced the tank and never had a problem after that.

Does your alarm have a constant sound if you just turn the ignition on. If it does, try disconnting the VRO wire and see if it stops.

posted 06-07-2005 07:14 PM ET (US)            

The tank did not go bad.. It worked just fine except that the alarm was sounding when it shouldn't. I disconnected the alarm for awhile before replacing the tank and had no problems.

I have never had a problem with VRO system, Pump or VRO Tank... except for the alarm.

posted 06-07-2005 11:55 PM ET (US)            

As luck would have it I spoke to the fellow who helped rebuild the engine before I bought it, he is a marine mechanic, has the identical year/engine Montuak as myself, and he invited me up to a local lake to go over the workings of my engine this weekend. While he does not feel that it's the impeller (they replaced it when they rebuilt the engine right before I purchased it) he promised to show me how to do mechanical maintanence, how to check for overheating, go over the workings of the VRO, thermostats,impeller, etc.

I definitely know for myself that I learn much better from watching & listening rather than just reading alone.

I'm very excited and hope, in short order, to be taking care of my boat, down to the last nut and bolt, with a decent amount of know how (bear in mind that I do not mean know all)and a fair amount of confidence.

One thing I realized today regarding my lack of knowledge with both the VRO and the engine itself, I am really failing myself. If a mechanic says I need this, this and this, and I don't have a good idea about how things work, then I won't know any better than to just nod my head and pull out my credit card. I hate that scenerio.

posted 06-08-2005 08:24 AM ET (US)            

You can re-fit some older OMC motors with an upgrade to add the SYSTEM CHECK feature. This will help you distinguish which sensor is causing the alarm. Or, you can familiarize yourself with the different cadence of the aural alarm for each sensor in your exiting system, and interpret it that way.

In spite of what appears to be an unstoppable amount of dock talk about the VRO system, its poor design, its role as the root cause of millions of dollars of engine damage, etc., in my opinion it seems to be a rather decent system which works well for most people. Far more than any other engine brand, its operation is closely monitored and provided with several alarms to warn of problems.

posted 06-17-2005 10:05 PM ET (US)            

The shop manual should be a lot like reading a recipe out of a cookbook (since we're on the home-ec analogy). You'll want to read a particular section through once or twice, then go shopping for parts after making a list of the extra items you'll need (take the service manual when you go shopping, just in case the parts counter has no clue what you're trying to accomplish). Once you're done shopping, the fun really begins.

posted 06-18-2005 11:51 AM ET (US)            

Hope I haven't derailed this fascinating thread, you two smokers...and I love you, beaufort; I chuckled at your first comment and almost fell off my chair at your second.

Tight lines, you Whalers. I sort of envy your arcane knowledge of and patience with those "classic" motors, but then again...