How to premix with a built in tank?

[riesesdad]

I just bought a new (to me) 1991 bayliner with a 90hp force outboard of the same year. I've mixed gas for many years for many toys, but I was wondering about doing it properly with a built in gas tank.

I usually add the oil so that it gets mixed while adding the gas, but with a built in tank, I won't always know exactly how much gas I will need to put in. In this case, I would have to add oil after I put the gas in.

I can't imagine filling up 5 gallon gas cans at the marina to mix gas, then filling the tank.

I guess my question is, will the oil mix properly if pour the oil down the gas tube after filling?

 

[ondarvr]

Re: How to premix with a built in tank?

It's pretty easy, fill the tank with gas, add the correct amount of oil and drive away, as you drive the fuel/oil mix will be sloshing all around and be mixed before you get a block away. If you want to make sure all of the oil is out of the filler tube, add one small shot of gas after you dumped the oil in.

 

[j442w30]

Re: How to premix with a built in tank?

Find out how much the built in tank holds and then based on your fuel gauge, estimate how much you're going to need to put in. Then when your filling, stop at an even gallon amount a little less than filling the tank totally full and add the appropriate amount of oil. Hope this helps.

 

[riesesdad]

Re: How to premix with a built in tank?

Both good suggestions. Thanks.

 

[tashasdaddy]

Re: How to premix with a built in tank?

you will get to know the guage, i estimate how much gas in need, measure it in the mix bottle, put 3/4 of it in first the fuel up, and add what else is needed. also if you over fill, and can't get the oil in, if on trailer drop the tongue, on in the water get passengers to go as far forward as possible. too much oil is better than not enough.

 

[riesesdad]

Re: How to premix with a built in tank?

What is this 'mix bottle' of which you speak?

 

[Esox]

Re: How to premix with a built in tank?

I think this is what TD is referring to:

http://www.iboats.com/2_Cycle_Oil_M...d.246639--list_time.1179509849--view_id.56142

 

[riesesdad]

Re: How to premix with a built in tank?

Ahhh, I see. I've never used one of those, but it would make my life a lot simpler.

 

[Chinewalker]

Re: How to premix with a built in tank?

The marina I worked at years ago, as a gas dock attendant, told us to add the first pint, then 6 gallons of gas, add a pint of oil, then the next 6 gallons of gas, and so forth. That way you were always mixing some oil in with the gas so that if you ended up a little off at the end you would be on the rich side - better than being on the lean side....

We also had people who would swirl the gas in a funnel as the oil was added to mix it in, maybe 4 oz. at a time or so...
- Scott

 

[tashasdaddy]

Re: How to premix with a built in tank?

walmart sells the bottles, makes life simple, as i buy by the gallon.

 

[ezmobee]

Re: How to premix with a built in tank?

One of those bottles saved my motor. When I first got my boat there was some discussion and fuzzy math about how many ounces were in a cup or something like that. Probably ran two tanks through. I bought one of those bottles and filled it up to the 50:1 line and was "oh my that sure looks like a lot". I had apparently been mixing 100:1. Dulp!

 

[Marc III]

Re: How to premix with a built in tank?

The marina I worked at years ago, as a gas dock attendant, told us to add the first pint, then 6 gallons of gas, add a pint of oil, then the next 6 gallons of gas, and so forth. -Chinewalker


That's how I do it unless I see it starting to fill up. Then it's 1/2 a pint of oil followed by 3 (or less) gallons of gas.

 

[Chief101]

Re: How to premix with a built in tank?

It's pretty easy, fill the tank with gas, add the correct amount of oil and drive away, as you drive the fuel/oil mix will be sloshing all around and be mixed before you get a block away. If you want to make sure all of the oil is out of the filler tube, add one small shot of gas after you dumped the oil in.

Exactly how I fill. One time when my gas guage said half tank I tried adding the oil first...I ended up running that tank at about 30/1. NBD just that it works fine for a trailered boat to add oil at the end when you know how much to use. Chief Chief

 

[Chief101]

Re: How to premix with a built in tank?

I think this is what TD is referring to:

http://www.iboats.com/2_Cycle_Oil_M...d.246639--list_time.1179509849--view_id.56142

I find the gas erases the ink that marks the oz graduations so instead I use a 32oz measuring cup. Chief Chief

 

[WillyBWright]

Re: How to premix with a built in tank?

Who wants to be a Millionaire? Make a quart plastic oil bottle measured in gallons @ 50:1 instead of ounces. White and translucent, or with that tracer down the side like so many of them have nowadays. But I'd like a royalty, please.

Ya'd think the outboard bottles would come like that anyways, wouldn't ya? I mean, like it's Rocket Surgery or Brain Science or something. Sheesh!

 

[Silvertip]

Re: How to premix with a built in tank?

Gas gauges are notoriously inaccurate and is not a good way to measure fuel remaining. As was suggested, fill the tank, note the gallons added, and simply add the appropriate amount of oil. When you bounce out of the service station driveway the oil will already be mixed. If you are not good at math, the back of any oil bottle has the fuel mixture ratios printed on the label. All you need to do is use multiples of what the label says.

 

[kenmyfam]

Re: How to premix with a built in tank?

Some oil in before you fill and the balance after you fill and you should not go wrong with it getting mixed O.K.

 

[jeeperman]

Re: How to premix with a built in tank?

I find the gas erases the ink that marks the oz graduations so instead I use a 32oz measuring cup. Chief Chief

Why is gasoline touching the oil measuring bottle?

 

[Chief101]

Re: How to premix with a built in tank?

Why is gasoline touching the oil measuring bottle?

When I am done filling the oil I put a little gas in the measuring cup to clean it up and pour into the spout thus the gasoline in the measuring cup. Chief Chief

 

[cwlandefeld]

Re: How to premix with a built in tank?

I gotta add my 2 cents. I bought my boat used in 2005. A 1992 VIP center console with a 1997 Evinrude 150 Ocean Pro and a 42 gallon built in tank. The guy I bought it from told me he thought he put too much oil in it (tank). He said it smoked alot. And it did. Now before I used it I went through this forum trying to find the correct oil to gas ratio. I then made a nice little chart to aid when I had to add gas. Funny thing (not) though is that this motor has a VRO meaning that oil is injeccted into the gas stream from a seperate oil reservoir (under the console). Found this out from a brother in law. Well needless to say, oil should not be mixed in my fuel tank. Unless the VRO quits. It only took about forty or so gallons of gas in the tank sans oil to get rid of the smoke.