Just like manually premixing the oil and gas, the VRO (OMS) automatically does the same thing and sends that fuel mixture to the carburetors. What standard pump can I use? Each engine revolution moves the piston (dark green) incrementally to one side of the air motor chamber (tan) and compresses the large spring. The quickest and easiest test is the grounding of the tan overheat temp switch wire to the engine block. What's left of Pine Island. Now you have richer gas oil mix with its resulting symptoms. VRO Pump Conversion To Straight Fuel Pump). There are indicator LED's for HOT, NO OIL, LOW OIL, and CHECK ENGINE (which means a fuel restriction in a V-6 carbureted motor). Each cycle pulses oil into the foamy mix, increasing the oil:fuel ratio to the carbs creating a smoky exhaust. "Uh huh, my neighbor had a blown engine, " quips another. Look for sediment or water settling to the bottom of the container. Surely some of them must have a pump that would work for me. 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.
It consists of four basic sections: Cutaway View of VRO Pump Showing Major Components. Since each carb receives the same oil to gas ratio, the VRO cannot cause only two cylinders to fail. Actually the engine works great when I become the fuel pump, but my hand gets tired and it's not allways easy to know where I'm going when I'm pumping the ball. One of the bones OMC owners like to pick concerns the oiling system. His engine is a 97 so most likely a looper which will NOT work with an old pulse style pump.
It's 2 stroke, I assume of course, carborated, and the model # appears to be 50plsoc. Since the VRO depends on crankcase pulses to operate, it is susceptible to backfires from a lean running cylinder or an out of tune engine. As you run out of fuel, the oil still pumps, filling the lines and carbs with your favorite TC-W3 lubricant. Here is the instructions I've found to disable it: ********************. CDI Electronics' #551-34PV gearcase vacuum/pressure tester work well, as does a SnapOn YA-4000 or the old Stevens pumps. As for the constant sounding horn at high speed that stops when slowing down, that's a fuel restriction warning, not a VRO malfunction.
Senior Refuge Member. In my case this wonderfull VRO that everyone raves about, and seems to run for the very low price off about $400. The air motor converts the pressure and vacuum pulses from the crankcase to a linear motion. You can use a clear piece of fuel line connected to the VRO inlet and "T" off to a vacuum gauge. I'm not the least bit mechanicaly inclined, but I'm learning, and several of of my more mechanicaly inclined friends and I have come to the conculsion that it must be the fuel pump. Re: Should I disable my VRO? Can anyone help me get a part number? The operator just had to keep the oil reservoir full and oiling would be done automatically. Each OMC (VRO) kit contains the parts needed including a new pulse limiter to install the system correctly. Video time control bar. Since 1993, the VRO is actually called an oil metering system (OMS). Unfortunately, the damage was done. OMC also makes a wiring harness adapter (P/N 174710) for the 1984 and 1985 engines that did not have any warning systems. Whenever there is a gathering of boaters, the conversation usually turns to engines, then gravitates to stories about problems.
VRO STORY—The Myth of the Mixer. If air gets into the fuel, it causes a foamy solution, similar to a head of beer in a tall glass. Early systems had a smooth vinyl oil line that hardened after a few years and sometimes caused air leaks. Gasoline reformulation in those early years contained alcohols and solvents that softened the internal rubber components and caused pump failures and damaged engines. You can also replace the clear plastic cap with the later model's solid black filler cap (OMC P/N 176217) that provides much better water intrusion resistance. 5 to to 3-inches of vacuum at full speed. Please review our Warranty, Returns & Refunds policies before you place an order. I've found countless sites online selling fuel pumps and I have many local marine stores in my area. Repair and update your VRO or OMS system methodically and by the service manual. If your motor is older than a 1993, make sure it has the blue colored pulse limiter to protect the air motor and the check valves in the pump. Reconnect the fuel hose.
The original VRO from 1984 and 1985 had a black fuel outlet fitting and no wiring. However I found this info elsewhere on the internet: Also, if I did swap to a regular pulse pump I would have trouble with the plumbing between the fuel pump and the carbs. The engine will still not run wide open, or sometimes at lower RPMs, unless you pump the primer ball. The VRO's electronic circuitry compares the RPM of the engine to the number of pressure pulses from the oil pump piston. Directly connected to the air motor is the fuel pump and the oil pump. VRO replacement and no fuel pressure fix. "Yeah, my boat smokes like hell at low speeds and fouls the plugs, " bemoans one boater. It WILL lean out on the top end as loopers have very small crankcase pulses at higher RPM's. On the other hand, the brother-in-law's motors (3) have two different year's pumps on them. In working with Sam with his older 210 equipped with a older VRO "Neverrude" that for the most part they were as strong as death...
In 1996, the SystemCheck® warning gauges were introduced. The travel of the air motor pumps the fuel and the oil together to the carburetors and the alarm system monitors the oil pressure counts. Gasoline is drawn into the blue area of the chamber, travels through the piston's flapper valve, and is pressurized in the green section on the following stroke. 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. The information provided on these pages is correct to the best of my knowledge, however the MasterTech makes no warranty, express or implied, regarding the use of, results of, or liability created from, application of this data. Trace the wires from the back of the VRO to its rubber plug (electrical plug) and disconnect it.