Evinrude VRO Question And How to Disconnect

[rickdb1boat]

I have a 1990 Evinrude 70HP with the VRO. I have read many reports of people disconnecting the VRO and going to mixing their own. The motor was rebuilt last year when I bought it and it seized up because the VRO went out. They rebuilt it again and installed a new pump and all the related hardware for the VRO. My question is, should I just do away with the VRO and if so, can someone be specific on the proper way to disconnect it, as I have seen many different posts on ways to do it, so I don't screw it up. I went for years mixing my own and never had a problem. Any help would be greatly appreciated! Thanks, Rick

 

[JB]

Re: Evinrude VRO Question And How to Disconnect

Howdy, Rick.<br /><br />Getting the VRO disabled is simple: remove the oil input to the pump and plug it.<br /><br />The electrical part is not as simple, because the location and types of alarm sensors varies from one type engine to another. You will need a manual or advice from someone who has one to find and disconnect all of the alarm sensors.<br /><br />Good luck.

 

[jegervais]

Re: Evinrude VRO Question And How to Disconnect

I know these engines pretty well and can finish up for you. Find the wiring harness that comes off the back of the VRO. Depending on the age of the pump it may have three or four wires, black, grey, tan and if it's a 4-wire, purple. The wires run to a round black rubber plug about 2" long & 3/4" in diameter. remove the spring-clip from it and un-plug it (it WILL be left disconnected or you will get false alarm signals). Next, find the 2 wires that run from the oil tank to the motor. Find the connectors and unplug them, pull the wires out of the cowl and remove the oil tank from the boat. Remember to premix at 50:1 and you're done.<br /><br />BTW - It's very important to inspect the capped oil fitting periodically. If the cap should fall off, it will allow contaminants to get into the pump and it will gum up and fail. If it ever does fail, there is a "premix conversion kit" for 3-cylinder & larger OMC motors (p/n 438402), that eliminates the oil pump section of the pump and cost about $100 less than a VRO.<br /><br />-John

 

[rickdb1boat]

Re: Evinrude VRO Question And How to Disconnect

Thanks for the help guys! I just worry about the VRO failing and blowing another motor. I would feel much safer if I knew for sure that I had the right mixture. Thanks, Rick

 

[rickdb1boat]

Re: Evinrude VRO Question And How to Disconnect

John, when you say "It's very important to inspect the capped oil fitting periodically" If the cap should fall off, it will allow contaminants to get into the pump and it will gum up and fail. Are you talking about after I remove the VRO and plug it at the motor? Why would I worry about it failing if I am pre-mixing my own? Guess I don't quite understand it completly. Also, could you go a little further about the "premix conversion kit" thing? I'm guessing that would eliminate the pump from the motor altogether??? Thanks Again, <br /><br /> Rick

 

[jegervais]

Re: Evinrude VRO Question And How to Disconnect

Rick,<br /><br />Are you going to physically remove the VRO pump, or just disable the oil injection function?<br /><br />If you're disabling the oil injection feature, that leaves the fuel pump portion of the unit in place.<br /><br />If you disable the oil injection feature, this is why you have to check things occasionally: <br />The design of the VRO unit incorporates an air motor, in which a diaphragm is driven by crankcase pressure and vacuum pulses. The air motor is connected via a stainless steel "rod" to a diaphragm style fuel pump and to a piston style oil pump. If contaminants get into the oil side of the pump, it may "jam" the oil piston in its bore. Since all 3 sections of the pump are interconnected by a "rod", the jammed oil piston will prevent the pump from functioning at all. Make sense??<br /><br />A premix conversion kit is a replacement "fuel-only" pump. It resembles a VRO (minus the oil pump section and alarm module). It costs about $100 less than a VRO and the beauty of it is it mounts in place and utilizes most of the same hoses the VRO did. This simplifies installation and the installer doesn't have to deal with fabricating brackets and ordering pre-formed hoses to retro-fit the old "house-shaped" fuel pumps. The retro-fit route is actually a little more costly in parts and labor. The premix conversion kit is the way to go IF and when the fuel portion of the VRO ever fails.<br /><br />-John<br /><br />BTW - periodically = 2 or 3 times a year. You just want to ensure the cap stays in place.

 

[rickdb1boat]

Re: Evinrude VRO Question And How to Disconnect

John, thanks for the extra info! I plan on just disabling the VRO for now, but I did'nt think about it also being the fuel pump as well! DUH!! I now understand why you would want to check on things every so often. A couple of more questions and I should be set: Will the fuel pump part last as long as it normally would with the VRO connected? Also by unplugging any of this at the motor, will it affect the overheat warning horn in any way? And finally, where can I get the conversion kit and would that be a problem to install myself or should I have it done? I think that's about it and I appreciate your help. Rick

 

[jegervais]

Re: Evinrude VRO Question And How to Disconnect

Answers (in order): Yes. No. Any JohnnyRude dealer. I think they're e.z. to install. I don't know your mechanical abilities, but if you're comfortable with this kind of work, have at it.<br /><br />Have fun!<br /><br />-John