VariableRateOiler

The Removal

How I disconnected the VRO and remove the oil tank.

By John Foster

After many months of deliberation, it was decided that it was time to disconnect the VRO unit and remove the remote oil tank from my 1993 90hp Johnson. Since the motor is 7 years old and way out of warranty. And hearing all the stories of the VRO failing. I had lost trust in the VRO. The decision was made easy after I discovered an oil leak in the hose from the tank to the motor. That was the last straw. As most of you know, any leak and or restriction in the oil line will result in less oil being mixed with the fuel. Possibly ending the motors life due to lack of oil. I know the motor was still getting oil, but was it enough? I could no longer trust the system. If there was an oil pressure gauge on the motor then I would trust it, but there isn’t one.

Below is a short article on how I disconnected the VRO and removed the remote oil tank. Some pictures are included to help you visualize what was done.

The first thing you need to do is remove the oil line from the motor. It’s a simple job. Just remove the clamp and pull it off the fitting. Make sure you have something to plug the hose and a drip pan to put under the motor to catch the extra oil that will spill out of the fitting on the motor. It’s not much oil, maybe a few tablespoonfuls. But enough to make a small mess.

Next you need to locate the wires that run from the remote oil tank to the motor. You need to disconnect them from the motor and pull them and the oil line back into the boat. You will need to loosen the clamp in the cowling to get the wires and the oil line out. Notice the large bundle of wires that were stored in the motors cowling. (I guess the person that rigged my boat couldn’t cut off the excess and crimp new ends.) If you had to cut any ty straps to get the wires and oil line out replace them now. After you have done this you can remove the oil tank. Make sure you have something to put the oil in. my tank had over a gallon still in it. If you are not going to use it in you gas. Please dispose of it properly.

After you have removed the remote oil tank from the boat. All that is left to do is cap off the oil inlet and disconnect the wiring harness to the VRO. Some people told me that I just had to put the cap at the fitting were you took off the oil line. I thought about it for a while, and decided to not only cap the fitting in the cowling. But to remove the hose from the VRO units fitting, and cap it off there also. My reasoning for this is sense the VRO is a Vacuum/Pump. It could suck water from the fitting if it was submerged. It could happen. So I removed the hose from the VRO units fitting and caped it off there.

The whole project took me about 2 hours. It is not hard to do. You just have to make sure you have what you need before you start. Nothing bugs me more than having to run to the store to get that 50-cent item to finish the job. You will need two 5/16 caps that are fuel and oil resistant. OMC part #315391 and clamp #322654 or go to your local automotive store and buy 5/16 vacuum caps. Just make sure they are long enough to get a snap clamp or special ty strap clamp on them. (The special ty straps you have to get from an OMC dealer. They have a special head design to seal all the way around the hose). OMC also sells a plug to install were you disconnected the VRO wires from. (#335655) I just used black electrical tape and sealed off the ends of the wiring harnesses.

Once you have completed blocking off the VRO fitting and Cowling fitting you are done. That’s it. You will however have to mix your oil and gas from now on though. But for me, the total piece of mind I get, knowing the motor is getting the right amount of oil, is worth the extra hassle of mixing my own fuel. One other advantage that I got from removing my oil tank is that I now have room for a fourth battery. Which I will use to run all the electronics on the boat, and to jump the starting battery if needed.

I hope this article will help you if you decide to disconnect your VRO system. I know that your motor may be different then mine. But the procedures will be very similar. All it takes is a little time and a little know how and you can do it.

John

All OMC part #’s are from my Johnson/Evinrude service manual Part #508285