What is a VRO outboard motor?
What is VRO outboard? Two-stroke outboard motors have traditionally used a mixture of gasoline and lubricating oil as their fuel. OMC introduced an oil/gasoline mixing system for their outboard motors in c. 1984, and called this feature a Variable-Ratio Oiling system or VRO.
What does the VRO do?
It's basically the same visual maintenance that you would give your fuel system.<br /><br />If you read all the internet posts about the VRO, it is the current and trained Johhson and Evinrude techs who know the system is fine. It is the untrained folks who think the VRO is bad.
What is a VRO fuel pump?
OMC introduced the VRO on the V-4 and V-6 engines in 1984. The pump consisted of a combination oil pump and fuel pump actuated by crankcase pulses through an air motor. Gasoline reformulation in those early years contained alcohols and solvents that softened the internal rubber components and caused pump failures and damaged engines.
Does my 1990 Evinrude have VRO?
My 1990 60HP Evinrude had VRO. Now it has a scored Cylinder wall and no compression on number two. Motor had 98 hours on it, alarm horn tested ok but never came on. You must log in or register to reply here.
What does VRO mean on Johnson outboard?
Sorrry, couldn't resist, it stands for Variable Ratio Oiling. Basically it works like most two stroke oiling systems by varying the amount of oil needed to mix with the gas for your motor.
How does a VRO fuel pump work?
8:3316:03Evinrude VRO pump and carburettor clean - YouTubeYouTubeStart of suggested clipEnd of suggested clipThis. I believe is a vacuum pulse that drives the pump. And then the top here is the oil fuelMoreThis. I believe is a vacuum pulse that drives the pump. And then the top here is the oil fuel mixture out that then goes off to the carburetors.
How do I know if my VRO pump is working?
Start the engine, and monitor the pump cycles by using a fuel pressure gauge or by putting light finger pressure on the outlet hose.At 800 RPM, the oil level in the hose should drop 1" in approx. 5 pulses.At full throttle, the oil level should drop 1" in approx. 3 pulses.
How do you change the VRO on a Johnson outboard motor?
2:325:31Johnson/Evinrude VRO Fuel Pump Conversion - YouTubeYouTubeStart of suggested clipEnd of suggested clipThis is pretty easy to remove. The first bolt is going to be up here this is going to be the firstMoreThis is pretty easy to remove. The first bolt is going to be up here this is going to be the first of all for the bracket.
When did Evinrude introduce VRO?
The VRO2® was introduced in 1986 and included a "NO OIL FLOW" alarm.
How do I remove the VRO from my Evinrude?
0:012:56VRO Removal Disconnecting VRO Capping Evinrude Johnson ...YouTubeStart of suggested clipEnd of suggested clipThis here already done this so I unscrewed this so I could get in here I followed the wires up IMoreThis here already done this so I unscrewed this so I could get in here I followed the wires up I took the ground unscrewed this here I removed the ground. And then I'm going to remove this as well.
How do you disconnect VRO Johnson?
0:222:02iboats - How to Disconnect VRO oil injection - YouTubeYouTubeStart of suggested clipEnd of suggested clipSo yep crack that black and Tran wha-at tan wiring and disconnect. It inside and just tuck it away.MoreSo yep crack that black and Tran wha-at tan wiring and disconnect. It inside and just tuck it away. The other key one comes off the VR oh here the vro.
How do I test my Evinrude fuel pump?
0:376:06Evinrude 9.9 Fuel Pump Test - YouTubeYouTubeStart of suggested clipEnd of suggested clipHere. It's a vacuum pressure gauge the vacuums over here pressure is going to be read at idle speedMoreHere. It's a vacuum pressure gauge the vacuums over here pressure is going to be read at idle speed this should be right around one pound.
How do you test a Johnson outboard fuel pump?
2:195:11How to check fuel flow on outboard - YouTubeYouTubeStart of suggested clipEnd of suggested clipYou can take a flathead screwdriver. With your flat-head screwdriver. You can check that there'sMoreYou can take a flathead screwdriver. With your flat-head screwdriver. You can check that there's fuel in the bowl of the carburetor. By just taking this brass plug.
How do you change a fuel pump on a Evinrude?
1:408:07How To Replace The Fuel Pump On an Evinrude 9.9HP Outboard MotorYouTubeStart of suggested clipEnd of suggested clipHere. Now the pumps off the engine except for the fuel line being connected to it. Now this is theMoreHere. Now the pumps off the engine except for the fuel line being connected to it. Now this is the small fuel line I disconnected earlier so you can just pull the whole pump right out.
How does a fuel pump work in a car?
The basic way your modern electrical fuel pump works is by utilizing a DC motor in the pump assembly which draws in the fuel sitting in your gas tank. From there, it sends it up the fuel line and into the fuel rail where it can be injected into a cylinder. It then mixes with air and a spark to create combustion.
What does VRO mean in oil?
The acronym VRO is for Variable Ratio Oiling, and the design goal was to reduce the oil/fuel ratio to around 1:100 at idle. This would imply that the engine ought to run more smoothly and be less prone to plug fouling because there was less oil in the fuel.
Does OMC VRO have oil ratio?
The latest versions of the VRO, now called the OMS for Oil Metering System or perhaps Oil Mixing System, do NOT vary the oil ratio over as great a range as in prior versions. There are no adjustments for the OMC VRO system.
What is a VRO on an outboard?
As the oil flows into the fuel area, the pressure moves a small piston that actuates a steel pin in the alarm module. The pin's movement is detected electronically and "counted." If the engine revolutions exceed the preprogrammed oil pulse ratios, the warning horn is activated sounding a rapid on and off sequence. Since 1993, the VRO is actually called an oil metering system (OMS). The ratio averages about 60:1, slightly leaner at idle and slightly richer at full throttle. The older pumps idled between 150:1 (prior to 1990) and 100:1 (1990-1992), then richened up to 50:1 as the engine load increased. They are recognized by the brown fuel outlet fitting and/or a wiring harness attached to the alarm module.
What is a VRO engine?
OMC introduced an oil/gasoline mixing system for their outboard motors in c.1984, and called this feature a Variable-Ratio Oiling system or VRO. Over the years some engine failures caused by lack of proper lubrication have been mistakenly attributed to defective VRO components. As a result, some owners of OMC engines with the VRO feature have disconnected the pump and reverted to pre-mixing. This article discusses the history of OMC outboards with VRO, the theory of VRO operation, and the diagnosis and repair of common problems. Suggestions for updating older motors are included. It also dispells some of the myths that have arisen in "dock-talk" about the VRO system. Earlier versions of this article have appeared in BASS & WALLEYE and TRAILER BOATS magazines, the AM-Tech newsletter, and other online resouces. A revised and updated version is presented here with the permission of the author, Bill Grannis, whom we thank for this valuable contribution to our REFERENCE section.
Why does the last guy blame the VRO?
The last guy (4) blames the VRO because he once had a car with a weak fuel pump and a replacement cured its hard starting problem. Actually, he only needs a refresher in the correct starting procedure. As for the constant sounding horn at high speed that stops when slowing down, that's a fuel restriction warning, not a VRO malfunction. A lack of oil flow is a pulsing on and off horn every second or so.
Why does my boat have foamy fuel?
For instance, the first boat owner's problem (1) is an air leak somewhere in the boat's fuel system causing "foamy" fuel instead of a solid column of liquid. This aerated gasoline has less volume and less resistance causing the fuel pump diaphragm to cycle faster. Each cycle pulses oil into the foamy mix, increasing the oil:fuel ratio to the carbs creating a smoky exhaust.
When did OMC introduce the VRO?
OMC introduced the VRO on the V-4 and V-6 engines in 1984. The pump consisted of a combination oil pump and fuel pump actuated by crankcase pulses through an air motor. Gasoline reformulation in those early years contained alcohols and solvents that softened the internal rubber components and caused pump failures and damaged engines. Back then, no company had alarm systems for a pump failure or loss of oil flow. OMC took care of the blown powerheads and improved the pumps considerably.
Where is the fuel pump located in a VRO?
The fuel pump, which is located in the middle chamber of the VRO, consists of a push-pull piston (orange) and diaphragm with a flapper valve and an inlet check valve. A rod connects the fuel pump piston (orange) directly to the air motor piston (dark green) and the two chambers are sealed from each other by an o-ring.
Does a VRO have an alarm?
Since the VRO did not mal function, there was no alarm to sound. On the other hand, the brother-in-law's motors (3) have two different year's pumps on them. The later model VRO's pump more oil at low speeds than the original ones did.
