Procedure for mixing oil

[clifton63]

I have a 50 gallon inboard tank. What is the best way to mix the oil. Do I add 16 ounces then pump in 6 gallons or can I add 32 ounces then pump 12 gallons. The bottom line is that I just want make sure the oil gets mixed well. Of course I cannot shake the tank. Does the oil just kinda mix itself over time?

 

[Chris1956]

Re: Procedure for mixing oil

The oil will mix pretty easily. However, On that size tank(if empty), I would put in 6 gal, and then add 32 oz oil, followed by 6 gal gas. Then I would shift to a routine where you put in a qt of oil and then 12 gal gas and repeat until full.

You do not want any just sitting oil on the bottom of the tank.

 

[Brewman61]

Re: Procedure for mixing oil

One thing not to do:

Pour several ounces of cold 2 cycle oil directly into the extremely cold gasoline in your 2 cycle snowblower's fuel tank because you forgot to pre mix it in the gas can. My father did just that.
The oil went straight to the bottom of the gas tank and was sucked into the carbureator, clogging it up. The carb was cleaned out and the engine eventually ran- and burned out because the fuel and oil never did mix.
Cold gas and oil don't mix as well as warm gas and oil!
But we did end up with a brand new snowblower!
Which was nice.
So in my opinion, he screwed up in reverse.

 

[dingbat]

Re: Procedure for mixing oil

Have a super secret way of doing it.

I climb onboard when nobody is looking and remove the rear seat cover. Slowly, I reach in and unscrew the cap on a 3 gallon tank. Make sure no one saw you. It wouldn?t be our secret if they knew. You then use a funnel to fill the tank with an oil formualted specially for your motor. If your in a bind, you could alway use the min. requirement stuff pushed by the oil industries version of the EOE. Anyhow, screw the cap back on the tank and replace the seat cover. Wipe your hands off and you?re done

Now, when you to mix the oil, all you have to do is turn the key. The rest is magic and you only need to fill the tank once every 150 gallons of fuel.

 

[Chris1956]

Re: Procedure for mixing oil

Gee, I thought that was my secret. How did he find out.....

 

[ThePartsMan]

Re: Procedure for mixing oil

The one that used to bug me was topping off.

If you poor in enough oil for 6 gal and only put in 3 you are rich.
Poor in 3 gal of gas and add enough oil then your oil is in the neck. Not mixed.

I finally started filling a 6g can and poured it in mixed right.

 

[glengold]

Re: Procedure for mixing oil

Get one of those oil mixing bottles with the graduations for several different oil mixes. might be 2 bucks at walmart

I like to fill until i hear it getting full, kinda hard to explain but I can hear the fuel getting close to squirting out the overfill port.

I measure the amount of oil I need based on how much it took, then add a 1/4 - 1/2 gallon's worth more of oil.

I then go back to pumping a little more fuel, enough to push the oil down into the tank.

I add ethanol treatment before my fill-up.

I've been at the pump before and expect she'll take 10 gallons and only takes 5, I sure am glad I didn't put oil in first!

Biggest trick is getting one of those graduated oil mixing bottles, you can use it for just about any 2 stroke since it has 100-1 through 24-1 mixes.

 

[Chris1956]

Re: Procedure for mixing oil

On a lot of boats the fuel gauge is accurate within 3 gal. 3 gal takes 8 oz of oil, so you can figure out how much fuel you will need to the nearest 3 gallons, and add appropriate oil. If you mess up, there is only a little extra oil.

 

[Home Cookin']

Re: Procedure for mixing oil

you don't have to worry about a precise mix especially on a large tank, but overall it is safer to be rich than lean. so, except for the empty tank (good point there) add the oil first, and the fuel treatment,then the gasoline. I do a pint then 6 gallons on my 20 gallon tank, and a half pint then 3 when it's getting full.

I also find most fuel guages to be worthless at the top end but all are different and with yours, you may figure out a trick.

If you have too much oil at the end of the process--say you added a pint and then 3 gallons--carry the three gallons and add it after you have run for a while. Yes I know that isn't exact since you've run out some mixed but this isn't rocket surgery.

 

[lcdr frank]

Re: Procedure for mixing oil

I buy my fuel in 5 gal jugs. Put oil and Stabil in before adding fuel. I always do this and only use 100% gas . Has worked out well for the last 5 years.I usually fill 4 jugs at a time and will use that much in a month if I make any long runs up and down the coast. My little 30 rude is dirt cheap to run.


Frank

 

[Chris1956]

Re: Procedure for mixing oil

Hey Home, If you add the 3 gallons of straight gas, after you have run the tank down 3 gal, you will be on the high side of 50::1, depending on the size of the tank, on the entire tank. Let's say you did that on a 6 gal tank (extreme example), where you had 3 gal of fuel at 50::1 and you added a pint of oil and 3 gal of gas. The first 3 gal of fuel would run at 32:1 and then you add 3 gal of straight gas to give you 64::1.

I would not recommend that to our members.

 

[ThePartsMan]

Re: Procedure for mixing oil

The worst one I had was when I got Grandpas old boat from my brother in law.

He poured a bottle of what the station had in when he filled it up.
Good new is the "fuel" was very dark when drained it out.

This is the same guy that called my every weekend for a summer wanting to know why it ran so bad before he mentioned the missing plug wire.

 

[AguaSki]

Re: Procedure for mixing oil

I buy my fuel in 5 gal jugs. Put oil and Stabil in before adding fuel. I always do this and only use 100% gas .

Exactly. I do this same process and use one of those measuring bottles that was previously mentioned. After adding the oil I can screw the cap on the jug and mix the oil with some good shaking. I also add some Sea Foam to each jug before pouring the fuel into the boat. This process takes a little longer, but I am anal about being exact with my oil and Sea Foam. I know that the fuel in my tank is exactly 50:1.

 

[Home Cookin']

Re: Procedure for mixing oil

chris I agree if you are using a small tank like a 6 but in that case you can see how much gas you need, and won't over-mix. An in-hull tank is bigger so if you run out 3 gallons of over-mixed fuel from a 50 gallon tank, then add 3 gallons, you aren't too far off--not enough to matter to the motor.
or look at it from the other direction: if my 6 gallon tank looks half full, I add a half a pint of oil then the gas. I might put in 2.5 gallons or 3.5 gallons (but I'd stop at 3). It just won't make any difference to the motor if it's off a little. Never has in my 40+ years of running them.
So the advice I give is to try to be precise but don't fret if you are off a little.

 

[Chris1956]

Re: Procedure for mixing oil

Home, I agree with you on a larger tank. You obviously understand the ratio varience and it would appear we have achieved som practical experience, in this area.

I was concerned that some of the newer folks might take too much license in this area, and miss the intended ration by a lot.....

 

[jeffer]

Re: Procedure for mixing oil

One thing not to do:

Pour several ounces of cold 2 cycle oil directly into the extremely cold gasoline in your 2 cycle snowblower's fuel tank because you forgot to pre mix it in the gas can. My father did just that.
The oil went straight to the bottom of the gas tank and was sucked into the carbureator, clogging it up. The carb was cleaned out and the engine eventually ran- and burned out because the fuel and oil never did mix.
Cold gas and oil don't mix as well as warm gas and oil!
But we did end up with a brand new snowblower!
Which was nice.
So in my opinion, he screwed up in reverse.

As i am a mechanical engineer. I have a good knowledge on oil. I like your concept. It is good.
So give you same but for proper knowledge you can read books.
Everything is explained vastly. There have enough books on it.
Ok take care.

 

[1fishbone]

Re: Procedure for mixing oil

I have a 50 gallon inboard tank. What is the best way to mix the oil. Do I add 16 ounces then pump in 6 gallons or can I add 32 ounces then pump 12 gallons. The bottom line is that I just want make sure the oil gets mixed well. Of course I cannot shake the tank. Does the oil just kinda mix itself over time?

My way of adding gas to a large tank:
I fill X amount of gas and add my oil and treatment for that amount I just put in,
then fill with X amount of gas and add the oil and treatment for that amount, AND AN EXTRA GALLON OF GAS, then add the last gallon.
(Make sense?)
My theory is, adding gas/oil/gas/oil/gas and by the time I get away from the fuel dock and through the 'no wake zone' that gas/oil/treatment is mixed.

The same theory if it's sits at the dock all week.
Acceleration/de-acceleration, getting around the moorings, through the 'no wake zone'...it's mixed again.

I also think gas/oil/treatment stays mixed over a long period of time.
One spring I checked my weed trimmer gas (2gallon jug, which sat undisturbed all winter) by pouring it into a clear container, then shake the 2 gallon jug and pour it into another container...there seems almost no difference in color.

I do know gas evaporates and the '2 gallon mix' which sat all winter is not 50:1 in the spring!

 

[Chris1956]

Re: Procedure for mixing oil

Gas and oil do not seperate. No worries there.

 

[skybobber]

Re: Procedure for mixing oil

Assuming you know how much fuel you need, add the amount of oil needed then add fuel, the process of adding fuel will give you a proper mix.

 

[Home Cookin']

Re: Procedure for mixing oil

fishbone, I suggest adding the oil first when you don't know how much you will be adding, so that you don't end up with a full tank and no room to add the oil. I'd rather be rich than lean.* And you can compensate later by adding a little gas, in a big tank.

I don't find there is an issue in mixing (as in shaking it up) as I think the turbidity from filling takes care of that.

*When I said, "I'd rather be rich than lean" it reminded me of the line in a Little Feat song:
I used to worry about things like that.
I used to worry about rich and skinny,
before I got poor and fat.