Mixing oil in Gas Tank vs using separate oil/gas tanks

[jdicke6]

I have a boat with a blown powerhead. It is a 1995 Johnson 225 ocean pro. I have read alot of articles about how ouboards are ruined because by the time the warning horn beeps the damage is done and your fuel doesn't have enough oil in it to prevent damage to the motor.

I have a separate oil and gas tank and I am thinking about just mixing all my oil into my 120 gallon gas tank so I don't have to worry about it.

I have also heard of some say that it is a good idea to put a really small amount of oil in the tank so that if something does happen and the oil tank is not pumping to the motor, the gas will still have some oil in it.

I have minimal knowledge about this stuff and I just want to get my boat on the water and prevent any kind of damage that could be prevented.

Main question is:
What would this effect by direct mixing oil and gas in the gas tank.
Do I need to disable something or make any changes so this works(how do I get the warning horn not to beep?)

Is there anything else that will be affected by doing this?

 

[Frank Acampora]

Re: Mixing oil in Gas Tank vs using separate oil/gas tanks

There are a number of pros and cons to both sides of the argument. Yes, by mixing oil in the tank, you know the engine has oil, but it takes a little thought and time. You need to estimate how much gas will be put in the tank and add the corresponding amount of oil. Many people do not want to be bothered. It also provides a constant ratio of gas to oil 50-1 so it uses more oil than the VRO pump supplies at partial throttle. Green people don't like this. VRO varies from about 100-1 at idle to about 50-1 at full throttle

I suppose that some year engines do have pumps that were known to fail regularly and I have heard a couple of OMC mechanics say to get rid of the VRO pump and use straight oil/gas mix.

On the other hand, OMC has in the past advised that even without oil, an engine that was properly lubricated before pump failure could run quite a long time at less than full throttle ( I think 2000 RPM was the number) on straight gasoline.

I really don't see much advantage to adding just a little oil to the tank, "just in case." Now, you have the worst of both worlds-- the bother of adding oil and the higher oil usage. In for a dime, in for a dollar! Either add the correct amount for 50-1 and don't use the VRO, or don't add any and continue to use the VRO. But that's just my take on it, and none of my engines are VRO.

And yes, there is a wire coming from the tank for low oil and from the VRO for no oil so unplugging these will disable the warning. Ask which wires over at the OMC forum.

 

[dingbat]

Re: Mixing oil in Gas Tank vs using separate oil/gas tanks

VRO STORY?The Myth of the Mixer

http://continuouswave.com/whaler/reference/VRO.html

 

[rodbolt]

Re: Mixing oil in Gas Tank vs using separate oil/gas tanks

decent article, mostly factual.
suzuki has had a low flow or no flow switch for some years on there oil injected two strokes.
most trained techs also reccomend replacing the OMS or VRO pump about every six years as a preventative maint action.
they dont fail very often but the occasional ones that do its catastrophic and usually renders the remains simply non rebuildable.
since the VRO2 was introduced I have seen 3 actual pump failures.
the rest the pump got blamed but was not the problem.
typically its either overheat or a carb leaned out.
over the years,to decrease emissions, engines have been jetted leaner and leaner and features such as back draft carbs have been used.
while it works very well it doesnt take much debris or trash to lean it out to the piston melting point.
same with the overheat.

 

[cub48]

Re: Mixing oil in Gas Tank vs using separate oil/gas tanks

Hi Guys
I have just bought a 1998 150 faststrike and was talking to my local boat shop about this same topic. I was told that at this age the vro could go out.
and it ran about 400.00 to replace it. I don't want to spend that much when I can premix. I read the link about the vro which sounds good. My question is how reliable is the no oil flow sensor. If it works I can always carry oil and premix if the light came on. or how much time do you have when the buzzer goes off. If you disconect the tank sensor and the four wire vro wire do you plug the oil line or just cut it and leave it open. unpluging these won't affect the other lights like the over temp and fuel restriction will it. I know I have ask a lot of questions but how do you learn if you don't ask thanks Steve

 

[rodbolt]

Re: Mixing oil in Gas Tank vs using separate oil/gas tanks

the 10 yr old tires on your truck may fail as well as the brakes.
its also why on those rubber diaphram pumps I always reccomended replacing them every 6 years or so.
rubber simply doesnt last forever.
that 400 dollars,broken down over 10 years, isnt much money as far as maint goes.
other than that make sure your alarm system is working. you should have system check on that version and it should alarm self test at key on power.