gas/oil mix time frame

[reefrunner7]

Talked with my Johnson/evinrude dealer today he told me I could mix oil with my 55 gal tank and it would be good for a year if I put something like stabil in it. Anyone got anything to say bout this? cause I've had guys tell me to use my mixed fuel within a month!

 

[Lone Duck]

Re: gas/oil mix time frame

Now you've done it ! The opinions will come aplenty . So I'm glad for the chance to be first. A year may be O K but I would not chance it. I would say 6 months at the most. And make sure the tank is FULL !! When you add the stabil Run the engine to make sure it is through all the system. Don't want that awful brown Gunk in your carb bowls . As for the boys that say 1 month, I would suspect that they are using some type of jerry can. I have found that if the cans are in the sun for any length of time some thing happens to make the fuel rot faster. If your fuel smells like varnish. It is past its best and could cause you trouble.

 

[smokeonthewater]

Re: gas/oil mix time frame

well I'm in the one month class..... on mixed 2 stroke

 

[Silvertip]

Re: gas/oil mix time frame

Treated fuel will be perfectly ok for six months. Up here in the tundra our boats, yard equipment and collector cars are stored for six months every year. We stabilize the fuel, run the engine to get the snake oil into the system and put 'em to bed. They pop right off in the spring.

 

[kenmyfam]

Re: gas/oil mix time frame

I agree. 6 months is no problem if properly treated. As Silvertip says, mix the stabilizer, run it till it's in the system and all will be well.

 

[smokeonthewater]

Re: gas/oil mix time frame

he isn't talking about long term storage of a boat he is talking about filling a 55 gal tank and using gradually over an extended time.... this is dangerous..... what happens is that as temp goes up and down every day/night the tank breathes... constantly drawing in air with moisture that condenses in the tank.... this water is readily absorbed by the alchohol in the fuel and at some point the alchohol reaches a state that causes phase seperation.... the oil stays in the gas and the alcohol / water builds up on the bottom of the tank with no oil in it.... when the engine starts picking up bits of this alchohol it will be running without enough oil.... If you want to go long term low maintenance on a big tank with a 2 stroke then hook your oil injection back up and pray that it doesn't fail.... pre mixing 55 gals of 2 stroke to use gradually over a season is a good way to shorten the life of your engine.

the adding of stabil allows longer storage but the tank needs to be completely full to avoid condensation

 

[JoLin]

Re: gas/oil mix time frame

Very good article here by David Pascoe on the subject of fuel tank condensation. Everyone ought to read it. In short, he concludes that it simply isn't an issue. I run out as much fuel as I can at the end of the season, treat the heck out of the rest, and don't worry about it.

http://www.yachtsurvey.com/myth_of_condensation_in_fuel_tanks.htm

I also go with the opinion that treated fuel is good for six months, or through the Winter as the case may be. I winterized my motor at the end of October with 10-15 gallons left in the tank. and will crank it up again in April. If I have any fuel issues I'll report it here.

Oh- I also don't like to fill the tank all the way and use it up too gradually. I'd rather add new fuel fairly often during the season. I fill to 3/4 and run down to 1/4. I generally visit the gas dock every 3-4 weeks

 

[NelsonQ]

Re: gas/oil mix time frame

I winterized mine from Nov thru April with stabilizer in it with no issues as well. I agree with the 6 months rule and following it in my weed whacker, lawn mower and snowblower.....no issues. But I think a year is stretching it.

But then again, with the use I put on my boat, 55 gallons is a long weekend of fun so I never experience keeping fuel in my boat past 2 weeks.

 

[Home Cookin']

Re: gas/oil mix time frame

One factor on how long the fuel stays "good" is your climate. Steady temps and cold temps, your fuel stays "good" longer. And some peole's experience in cold climates would not work for those in the tropics.

On the "attract water" issue: I'm no chemist but it was explained to me that one of the funcitons of stabilizer is to leave a layer on top of your fuel to keep it from contact with moist air. Makes sense but I can't verify.

 

[seaboo]

Re: gas/oil mix time frame

Just a point....Doesn't MOST 2 cycle mixxing oil have a stablizer built in??? I know my lawn mix has it built in and Yammalube does.....

 

[reefrunner7]

Re: gas/oil mix time frame

thanks men, I'm gonna drain the tank and start new. I feel confident after all your posts that I can fill it and make sure I stabil it as long as I run it out in say 3 months time I will be safe and safer than hooking the oil can injector back up

 

[smokeonthewater]

Re: gas/oil mix time frame

3 months probably isn't pushing it too bad, and you will have less trouble if you use it often than if you let it sit with a near empty tank for 3 months...... fyi the fuel doesn't absorb water out of the air but rather the water condenses on the inside of the tank and runs down the side to the bottom where it pools.... in the old days before methanol in gas it stayed there until there was enough (could take years) to be picked up and the engine would die because water doesn't burn.... now it joins with the alchohol in the gas and becomes a burnable substance (although it doesn't burn well and will cause a miss) but in a 2 stroke engine it is a burnable substance without the needed oil......

Knowing this you should be paying attention (you should any way) to how your engine sounds.... you should also know what your plugs normally look like so that if the engine starts to sound funny (especially when the boat is at certain attitudes) you can check the plugs or shut off and pump some fuel into a can for inspection.... you would look for a white liquid .... I have seen it with my own eyes so I can tell you that reguardless of any article it does actualy occur


EDIT: I have run all sorts of high performance 2 stroke engines for over 20 years.... I have seen all sorts of failures and 90% are from lack of oil or dirt ingestion.... the second one is not a big issue on a boat but the first is... The ideal situation is to purchase and mix the fuel as you use it..... Nobody here wants to give you bad info but quite a few aren't even understanding your question.... Many of these answers are aimed at 4 strokes and many are aimed at long term storage.... the oil and gas do NOT un-mix but with the addition of water the alchohol and gas can and do seperate. your enemy here is having a large air space in the tank as you run it down over an extended period of time.

There really is no perfect answer to your situation that doesn't require you making changes in what you want to do.... big tank, slow usage, and removed oil inj. That is just not an ideal combination.... I would either use the oil inj or use smaller tanks and mix each time I went out

 

[reefrunner7]

Re: gas/oil mix time frame

I want to take advantage of the size of the tank so if I can mix the 55 gal and run to fishing spots it may last 3 months I really don't know, I would imagine trailoring back and forth would keep it mixed up. Question? should I add stabil or like product to it right away? what do you guys do?

 

[Home Cookin']

Re: gas/oil mix time frame

add stabilizer when you put in fresh gas. Add some now if you don't have any in there, but remember, stabilzer won't restore bad gas. It just helps maintain the status quo.

 

[Cricket Too]

Re: gas/oil mix time frame

The only stabilizer worth anything these days is StarTron. You have to treat the Ethanol in the fuel these days more than you have to worry about the fuel going "stale". Stabil makes an Ethanol formula as well, which is pretty good, but I am loyal to StarTron after years and years of use, and seeing first hand how well it works. Regular Stabil is useless for preventing phase separation within Ethanol fuels. It won't matter how long it keeps your fuel "fresh" if it doesn't treat the Ethanol in the fuel and prevent Ethanol related problems.

I'm not sure if you are talking about using a 55 gallon drum to fill your boat throughout the season or if you have a 55 gallon tank on your boat, but I assume it's a drum your using to fill you boat tank, since you say 55 gallons will last you 3 months. 55 gallons will last me a weekend, or a 1/2 a day if it's an ocean fishing trip, so I've never stored that much fuel other than in my boat, and it doesn't last 3 months.

My brother's boat has a 250 gallon tank, he fills it in the Spring and it lasts him until mid-end of the summer usually July sometime, he doesn't use his boat for many long trips, just out to the bay and anchor and back. Because of this I double treat his fuel in the Spring with StarTron because I know that 250 gallons will be sitting in the tank slowing getting burned for 3-4 months, by the time he puts more in, there is about 50 gallons left which gets mixed in with the re-fill.....in over 20 years he has never had ANY problems.

Now on the issue of the 2 stroke oil coming out of mixture, you should probably not spend any amount of time worrying about that at all, that will not happen in 3 months, or 6,7,8 or 12 months. And if for some reason that does concern you, then just go ahead and re-hook back up your oiling system, (VRO, OMS, not sure what motor you are running), I'm not even sure why you would disconnect it anyway, they are completely safe and reliable, please, please, please DO NOT listen to all the BS hype about them being spewed by "internet mechanics" who have no experience with them or have any idea of where the BS rumors came from.

I have been running these systems on all types of engines since they first came out, and have never had or seen any major issues caused by them. Some of the original systems had some drawbacks, but they were blown WAY out of proportion by bad, dishonest mechanics trying to get more money out of people. There has been countless amount of discussions on it here, if you Search you will see plenty of experts explain why they got the bad rap they did. ANYBODY who says they aren't safe or anything to that effect, has absolutely zero idea of what they are talking about. I would say that there probably CANNOT be a safer system than what is already being produced. In fact I don't trust a person mixing their fuel as much as I would trust any automatic oiling system. I've seen way more people forget to add oil or not add enough, than I have seen issues with oiling systems.

 

[smokeonthewater]

Re: gas/oil mix time frame

here read this
when they say oxegenated fuel.... in general that refers to modern gasoline with ethanol added. I did see a point here that could be a benefit to you.... while this article was mainly intended for the atv/dirtbike crowd they did mention closing the fuel vent in storage.... If you had some sort of pressure relief valve you could close the main vent off when not in use to limit the "breathing" of the tank and as such limit the condensation... you will notice tho that even the manufacturer of the oil says to use "good fuel management" and "only buy and mix the fuel you will use within 2 weeks"
If there were actually an additive that could stop the absorbtion of moisture and thus phase seperation it makes sense that the manufacturers of 2 stroke oil would put it in their oil and advertise it as being specifically for extended storage of fuel instead of saying not to store fuel.

Most of the oil manufacturers have 800 numbers on their websites... If you still have questions I suggest that you call them and ask the folks who actually make the oil you plan to use. They spend millions researching and testing for a reason
...... best of luck to you and happy fishing

 

[Fisherball]

Re: gas/oil mix time frame

I hate to throw a wrench in somebody's ideas but... When I bought my first boat, powered by a 70 hp Johnson, it had been sitting from 2000 to 2004. Had 8 or 9 gallons of mixed, stablized fuel in it. I didn't know any better so I used 5 or 6 gallons, filled the tank & haven't had any problems at all. I was happy I didn't have to buy gas to use the boat.

 

[Home Cookin']

Re: gas/oil mix time frame

Your gas predated the ethanol problem.
When people frame their advice on the gas issue with "I've been doing this for 30 years" only the last 4 or so count. Just on the gas issue. But that also depends on where they live, too.

 

[Fisherball]

Re: gas/oil mix time frame

That's what I thought! The gas was too old to be effected by being old.

 

[reefrunner7]

Re: gas/oil mix time frame

I'm running a 1985 johnson 120 and as per everyone on here I removed the vro oil tank and will mix the oil and have a 55gal tank in the floor of the boat, I just was not sure fishing in the chesapeake just running out and finding a spot here and there how long or what my fuel consumtion would be. After reading all the advice and articles here I do feel safer just mixing my fuel do to the age of the motor and all parts (hope I'm doing the right thing) So stabilizer (star-tron) with every tank and plug up the vent hole for long storage to reduce condensation, I'll give it a try just in time for big stripers around "north east" md. You guys are great!!!