Fixed tank gas/oil mix question

Hermanclick

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Jul 23, 2013
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28
I currently use a portable 6 gallon tank on my glasspar runabout.I want to start using the fixed 12 gallon tank that is in the bow.I have scoped the tank and fitted a new line back to the ob since it has not been used in years.The boat will be fueled up and topped off on the water as it is dry slipped not trailered.What is the proper way to preform the oil mix in this situation?

Some days I might need 4 gallons and some days maybe 8 gallons of fuel.I can calculate the oil mix but I won't know how much I need until after I add the fuel so the oil will go in last. How do I mix it properly? I cant shake the boat.Maybe I'm just over thinking it.

Tia
 

Grub54891

Admiral
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Jun 17, 2012
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6,142
Re: Fixed tank gas/oil mix question

Mix the oil in a seperate gas can,just one gallon will do. When ya fill up,stop short. Add the correct oil to the gallon can,put it in the boat tank,finish topping off and if needed add more to the tank. Or just do what I do,fill up add tge oil,drive to the ramp,running down the road shakes it up on it's own.
Grub
 

Bob_VT

Moderator & Unofficial iBoats Historian
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May 19, 2001
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26,065
Re: Fixed tank gas/oil mix question

I do this method quite often........ I have an onboard 12 gallon tank. I use a regular gas can (5 gallon) but only mix 3 gallons at a time with 8 ounces of tcw3 (50:1) then transfer it to the onboard tank. So, on my way to the lake I always top off that 3 gallons and add it. After a few trips out, you will figure your consumption and work out a method. I could fill the entire 5 gallons and add in 13 ounces of oil.......it depends on what I need.
 

Chris1956

Supreme Mariner
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Mar 25, 2004
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28,080
Re: Fixed tank gas/oil mix question

A third way is to estimate how much fuel you will need in 3 gal increments. Toss in 8oz oil and add 3 Gal gas. Repeat as required.
 

Hermanclick

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Jul 23, 2013
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Re: Fixed tank gas/oil mix question

Thanks for the suggestions looks like the general consensus is mix then fill.I think a standard 5 gallon will do it for me hopefully they allow this at the pumps on the water.
 

Chris1956

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Mar 25, 2004
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28,080
Re: Fixed tank gas/oil mix question

No, you do not need to mix gas and oil in another tank. Simply toss in 8 oz oil and pump 3 gal gas. Then toss in 8 oz oil and then pump 3 gal gas. It will mix instantly, if you do that.
 

ondarvr

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Apr 6, 2005
Messages
11,527
Re: Fixed tank gas/oil mix question

Most tanks will fill and the nozzle will shut off, then burp (baffle near fill spout, you may need to shake the boat slightly), this burp typically allows more space for fuel or oil in the tank. After the burp put the oil in. If you fill too slowly the nozzle may not shut off soon enough and there may be no space for the oil. (just like topping off the tank in your car)

On large fuel tanks there may not be enough space for the amount of oil needed, but in a 12 gallon tank that isn't empty you shouldn't have a problem.
 
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Hermanclick

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Joined
Jul 23, 2013
Messages
28
Re: Fixed tank gas/oil mix question

No, you do not need to mix gas and oil in another tank. Simply toss in 8 oz oil and pump 3 gal gas. Then toss in 8 oz oil and then pump 3 gal gas. It will mix instantly, if you do that.

Thanks for clearing that up that will work better for me as I'm trying to eliminate lugging around a gas can.hopefully the old gauge is accurate
 
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JimS123

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Jul 27, 2007
Messages
8,235
Re: Fixed tank gas/oil mix question

I calibrated my gas gauge. I know exactly how much gas it will take beforehand. Throw in x oz. of oil, then add the gas. Its always right.

My buddy didn't have a working gauge, but the tank was poly and you could see the level. We put hash marks on the tank when we calibrated it so he can always see how many gallons he is down.
 
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