Johnson 70HP VRO

[VaGent]

I have a newly aquired 1987 Johmson 70 HP VRO that I would like to remove the VRO setup & just hand mix my gas/oil. Can anyone advise me what needs to be done to accomplish this? I'm a "fair" mechanic but have no idea what needs to be done. I've been told that most all the boaters are doing this to their engines as the VRO system is not that reliable. Any help would be greatly appreciated. Thanks

 

[dajohnson53]

Re: Johnson 70HP VRO

I have a newly aquired 1987 Johmson 70 HP VRO that I would like to remove the VRO setup & just hand mix my gas/oil. Can anyone advise me what needs to be done to accomplish this? I'm a "fair" mechanic but have no idea what needs to be done. I've been told that most all the boaters are doing this to their engines as the VRO system is not that reliable. Any help would be greatly appreciated. Thanks

Disconnecting the VRO and using premix fuel may or may not be the best thing for you to do. Depends on your circumstances. But I don't believe it is true to say "most all the boaters are doing this to their engines as the VRO system is not that reliable. "

Here's some helpful background info:http://continuouswave.com/whaler/reference/VRO.html

From my own experience, I prefer the VRO (OMS) mixing pump and with proper maintenance, I believe it is as reliable - at least - than the possible error of a human premixing fuel. I feel that the chance of me forgetting oil and/or making an oil error topping off my built in tanks was more likely when I premixed than now that I use a VRO/OMS pump. Plus, when I was premixing, if I were to forget to add oil, there would be no warning horn reminding me, until the engine overheated. With a VRO/OMS pump, there would be a horn when the tank was getting low or if the oil flow stopped or was inadequate. But that's just one opinion.

All that said, it's very easy to disable the oil mixing portion of the fuel pump and convert to premix.

 

[kenmyfam]

Re: Johnson 70HP VRO

Changed my 140hp to premix in July when the VRO pump started failing. I now have a "50 to 1" sticker on the gas tank filler and all the jerrycans that I use for the boat. Being in Canada we buy in litres so I put the oil in the can or tank before the gas. So far so good. I also know that if the fuel is getting through so is the oil !!!!

 

[VaGent]

Re: Johnson 70HP VRO

Thanks for the reply. The reason I stated "most of the boaters" is because that is what I am being told by a local marine mechanic. After reading the above link you kindly provided, I tend to disagree with him. I tested the engine on a 20ft pontoon boat at WOT & at idle & it seemed to run perfect for me but keep in mind I am by no means a marine mechanic. A question that does come to mind is this. Where would the oil tank be located on a pontoon boat & how big would it be in physical size? I do not recall seeing one anywhere when we tested the boat & engine. Thanks for the helpful information.

 

[dajohnson53]

Re: Johnson 70HP VRO

Thanks for the reply. The reason I stated "most of the boaters" is because that is what I am being told by a local marine mechanic. After reading the above link you kindly provided, I tend to disagree with him. I tested the engine on a 20ft pontoon boat at WOT & at idle & it seemed to run perfect for me but keep in mind I am by no means a marine mechanic. A question that does come to mind is this. Where would the oil tank be located on a pontoon boat & how big would it be in physical size? I do not recall seeing one anywhere when we tested the boat & engine. Thanks for the helpful information.

I don't know what kind of compartments your boat has that might hide it, but the oil tank will be ~ 2 gallon tank roughly the size of a car battery, with a fuel type hose with a primer bulb. The tank is usually a transluscent/whitish plastic and sometimes has a black top on it, sometimes not. The bulb is just like the gasoline primer bulb, but might be smaller.

If you have an intact oil mixing system, there should be two fuel-type hoses leading to your engine. Both may be connected directly to the fuel pump in your engine, or one might be a quick-connect type fitting which is common with portable fuel tanks. Either way, trace these two fuel hoses to their origin. One should go to a gas tank (portable or built in) possibly via a fuel filter. The other should go directly to the oil tank.

If you don't have an oil tank, you should be premixing the fuel 50:1 gas to oil. Were you told to do that?

 

[VaGent]

Re: Johnson 70HP VRO

I don't know what kind of compartments your boat has that might hide it, but the oil tank will be ~ 2 gallon tank roughly the size of a car battery, with a fuel type hose with a primer bulb. The tank is usually a transluscent/whitish plastic and sometimes has a black top on it, sometimes not. The bulb is just like the gasoline primer bulb, but might be smaller.

If you have an intact oil mixing system, there should be two fuel-type hoses leading to your engine. Both may be connected directly to the fuel pump in your engine, or one might be a quick-connect type fitting which is common with portable fuel tanks. Either way, trace these two fuel hoses to their origin. One should go to a gas tank (portable or built in) possibly via a fuel filter. The other should go directly to the oil tank.

If you don't have an oil tank, you should be premixing the fuel 50:1 gas to oil. Were you told to do that?

Thanks for the reply dj. When I looked at the 'toon I noticed 2 red tanks mounted on each side of the stern. One I know for a fact was gas & I "assumed" the other was for gas too as it appeared to be about the sme size. I did notice 2 lines with primer bulbs going to the engine but I failed to ask any questions as we didn't have much time to do a lot of asking at the time. Ijust took for granted it had twin gas tanks at the time.

I am going down to the 'toon today to do some measuring & I will definitly look it over more carefully to see about the oil tank. The engine cranked up easily & ran excellant & I did not notice it being a VRO (at least that is what is on the engine cover) until I was leaving to go home. I failed to ask if it was indeed a VRO or not.

Being this is my first 'toon it looks like I have a lot to learn & maybe learning it the hard way. For no more then I had to pay for the whole outfit (boat, motor & everything else thrown in) I suppose I can't complain as I failed to ask questions I should have asked. I greatly appreciate your help & information. I'm not too sure right now if this is going to be a "fun" learning experience or a "bad" learning experience. Either way I own the boat now so no matter what problems I encounter I have to get them fixed.

 

[dajohnson53]

Re: Johnson 70HP VRO

Just curious what you found out- sounds to me like dual gas tanks.

 

[kenmyfam]

Re: Johnson 70HP VRO

Here is the standard VRO oil tank. See if you have one !!!!
Let us all know.