Mercury 80 hp portable fuel tank

Kissdude

Petty Officer 3rd Class
Joined
Sep 7, 2024
Messages
95
Ok I have a silly question. As I was leaving town I filled my newer tank full of gas and added my oil. if it didn't mix too well could this be why it stalls when I try to leave the dock?
 

jimmbo

Supreme Mariner
Joined
May 24, 2004
Messages
13,750
I know this will get Responses that I am full of it, but having dealt with these Motors for over 50 yrs and seen what Improper Mixing does...
It still needs Agitation, mixing to mix. Pouring the Oil in to a tank, then adding fuel doesn't do a great job, filling the Tank, then pouring in the Oil is really Not Good. The Oil, being denser than Gas, will settle on the Bottom and initially you could have a very Oil Rich Mix, and as the Tank Empties, a 400:1 mix...
Trying to mix a full Portable Tank by tipping it, doesn't really do much as the Tank just revolves around the Liquid inside. Putting half the gas in, then adding the Oil, shaking back and forth a few times, so the mix sloshes against the sides of the Tank does a fair job, adding more Gas, hoping for a swirling Action to evenly Mix the fresh gas.
Filling Built in Tanks is best done with a Large Funnel, where you can add Oil as you add Gas. Works best if you don't fill the Tank up completely
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,188
As was said. 2 cycle oil mixes very well with gasoline, especially in a portable tank. The 2 cycle OB OEMs recommend you put 1 gal of gasoline into a portable tank and then add the oil. Now shake the tank to mix it. Now fill the tank.
 

cyclops222

Commander
Joined
Mar 21, 2024
Messages
2,251
I do it slightly different.
I usually has a gallon left in the gas tank when I switch to the spare 2nd 6 gallon tank. At the gas refueling dock I pour the oil FIRST into the tank. Then take the gas nozzle and put it into the tank. Pull the trigger to start gas at FULL FLOW RATE !! I then move the nozzletip in figure 8 patterns until full. That figure 8 pattern takes about1.5 to 2 seconds each time. Fantastick constant mixing of all the gas and oil in the tank. I use the 100 to 1 ratio on the ancient 2 strokes. motors run any nice day4 months every summer. 2 strokes are the TOUGHEST motors ever made.
 

cyclops222

Commander
Joined
Mar 21, 2024
Messages
2,251
DO NOT run the engine on that BAD mixture !!! have it pumped out !!!
Refill it correctly.
Any marina should have a pump to do it safely. Almost for free.
 

cyclops222

Commander
Joined
Mar 21, 2024
Messages
2,251
I have used 100 to 1in both Evinrudes since 1999. Engines are stored in upstate N Y. NO fogging was / is ever done.
Wear tests have confirmed that 330 to 1 is perfectly safe for normal use.
Bless all the fearful people. Keep oil companies in 300 foot yachts.
 

airshot

Vice Admiral
Joined
Jul 22, 2008
Messages
5,514
Today's new two stroke oils almost mix themselves, just ask any oil mfgr. Back in the days of mixing 30 at oil, you almost needed a mixer to combine them. If you want to test this for your self....take a gallon clear glass bottle and add two oz of good two stroke oil...( I use Pennzoil and have for 40 years) after the jug was filled with fuel and see how fast it mixes on its
own ! The slightest shake makes the whole gallon turn blue in an instant.
In the old days I went to great lengths to be sure my 30wt was mixed well, but for the past 25 years or so, add oil to the tank then fill with fuel, using the nozzle to help stir just as the oil mfgrs recomend, never an issue.
 

jimmbo

Supreme Mariner
Joined
May 24, 2004
Messages
13,750
You can do whatever you want, it is your motor, and your money...
I will Never assume the Oil and Gas mix themselves. They have different Densities...
 
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