Don't Understand Oil Injected Outboard. Always had ones I had to mix with fuel.

[E_S_A_D]

So, I am considering buying a boat with an onboard fuel tank. 45 horsepower Mariner engine that is 'oil injected'. Seller indicates only have to add gas and he believes it's a 4 cylinder. How's this work? Does more oil get added when it gets winterized? Or is it like a car that uses the same oil and then when it gets winterized the oil gets changed. Completely confused on this. Also, a 4 cylinder motor, is this good?
http://i.imgur.com/jtFY54o.jpg
Please help explain...

 

[Bob_VT]

Re: Don't Understand Oil Injected Outboard. Always had ones I had to mix with fuel.

Seller indicates only have to add gas and he believes it's a 4 cylinder.

Scary that the current owner is not sure.......might indicate a lack of maintenance. So....if you buy it plan on investing in a new impeller, a carb cleaning and I would probably flush the oil tank and lines too.

With the on-board fuel tank it will be nice not having to mix the fuel and oil.

Yes the oil is injected/mixed in the motor as it runs.

 

[E_S_A_D]

Re: Don't Understand Oil Injected Outboard. Always had ones I had to mix with fuel.

Scary that the current owner is not sure.......might indicate a lack of maintenance. So....if you buy it plan on investing in a new impeller, a carb cleaning and I would probably flush the oil tank and lines too.

With the on-board fuel tank it will be nice not having to mix the fuel and oil.

Yes the oil is injected/mixed in the motor as it runs.

Is it possible a boat if it got filled once by the marina could be good for the season on one fill up of the oil tank on an oil injected boat?

Does an oil injected boat have to have oil added everytime you fuel up? Still a bit confused, always had the old fashion type.

 

[E_S_A_D]

Re: Don't Understand Oil Injected Outboard. Always had ones I had to mix with fuel.

The boat runs great and sounds well maintained, but the seller has had to just add fuel. I'm lost.

 

[foodfisher]

Re: Don't Understand Oil Injected Outboard. Always had ones I had to mix with fuel.

Filler up and check the oil.

 

[82rude]

Re: Don't Understand Oil Injected Outboard. Always had ones I had to mix with fuel.

I think what the owner is saying is you don't add oil to the gas tank.look under the cowling of that motor and you will see a oil tank .it is a 4cylinder 2 stroke outboard.you will have to check the oil tank periodically as the mix I believe is 50:1 and not variable as in some of the new motors.good rule of thumb is fill up the gas and check the oil level everytime you fill up .

 

[Chris1956]

Re: Don't Understand Oil Injected Outboard. Always had ones I had to mix with fuel.

The oil injected (non-DFI) Mercury's have a crankshaft-powered oil pump that pumps 2 cycle oil into the gasoline line, at the fuel pump. The fuel pump completes the mixing and the carbs get a variable amount of oil in the gasoline, depending on the throttle setting. The throttle is synchronized to the oil pump, so the oil ratio can be varied. I would expect to see a 50::1 ratio at near full throttle, and a higher ratio (say 100::1) at idle speed.

You might post a question about the reliability of the system in the Merc forum. I have not heard consistantly good things about Merc VRO systems of that age.

 

[nwcove]

Re: Don't Understand Oil Injected Outboard. Always had ones I had to mix with fuel.

The oil injected (non-DFI) Mercury's have a crankshaft-powered oil pump that pumps 2 cycle oil into the gasoline line, at the fuel pump. The fuel pump completes the mixing and the carbs get a variable amount of oil in the gasoline, depending on the throttle setting. The throttle is synchronized to the oil pump, so the oil ratio can be varied. I would expect to see a 50::1 ratio at near full throttle, and a higher ratio (say 100::1) at idle speed.

You might post a question about the reliability of the system in the Merc forum. I have not heard consistantly good things about Merc VRO systems of that age.

just for reference sake.....100:1 is a lower ratio than 50:1.

 

[Chris1956]

Re: Don't Understand Oil Injected Outboard. Always had ones I had to mix with fuel.

I think it depends on what side you view the ratio.

A 100::1 return on your savings is a higher return ratio than a 50::1 return on your savings. Of course a .411 gear ratio is considered a lower ratio, compared to .303 gear ratio.

 

[ondarvr]

Re: Don't Understand Oil Injected Outboard. Always had ones I had to mix with fuel.

You have 3 or 4 threads going on this same basic subject, they should either be combined or some closed so people can follow this adventure.