Using the old gas, or diluting?

[Home Cookin']

In the constant ethanol battle I find conflicting strategies and would love to have the collective wisdom of the members: whether it's more important to keep the tank full or use up the fuel.

In addition to keeping the gas treated (startron and ringfree), and changing the seperator at 50 hours, I keep the tank full. The boat stays in the water year round, so I top it off whenever I run out 10-20 gallons--in part b/c I use jerry cans, and have 4, and don't want to make 2 trips, although sometimes I do.

I ran the boat a lot in the summer until about October, and then often (every week or so for a couple of hours) until Dec. 31. Since then, I take it out for 30 minutes to an hour every 2-3 weeks--just to run the motor. But I never just start it to let it idle at the dock.

Now the weather is warming up, so I'll be more likely to run it on the weekends in march/April, and more when fishing starts April/may. Here's the question: should I try to (a) run the tank down almost to empty, to get rid of all the gas and replace, even if that means sitting half full for a week or two.
(b) run out 40 gallons and refill 20, repeat until it's down
(c) continue to top off with 10-20 gallons fresh gas each time?

In the summer when it's hot the condensation is worse so I know to keep it full then. temps are cool now. Obviously I believe the best thing for a motor is to run it.

I really don't want to run out $200 gas (and hump that much down the pier all at once) but it's cheaper than another carb job!

Stats: 2004 Yam 150 TXRB (carbs) 80 gallon belly tank; Yam water seperator. Carbs were done this fall and last weekend, it ran great and hit good numbers at WOT.

 

[Silvertip]

Re: Using the old gas, or diluting?

Keep doing what you are doing. Gas -- ethanol blended or not is not old gas until is four or five months old. Blend it with fresh and it is only "half-old" fuel. We in Minnesota have used ethanol blended fuel since 1997. Collector cas and our boats run on the stuff and they are both stored for six months of the year. There aren't any issues if the fuel system is taken care of which yours is.

 

[5150abf]

Re: Using the old gas, or diluting?

3 months isn't long for gas, certianly not long enough for it to go "bad" and I don't think you need to do anyhting really.

My last trip was Thanksgiving, I will keep my tank low at the end of the year and next week when I get the boat out I will top it off with fresh gas and off we go.
I od drain my carb for the 4 month sit though.

 

[dingbat]

Re: Using the old gas, or diluting?

I don't do anything any different than I have for the past 10 years. I fish right up until December 31 if possible. Never know when the last day of the year will be. Start adding stabilizer in December. Typically end up over wintering right around a 1/2 a tank. Top off in Mid-March (next weekend ) when I start fishing again.

Never had any real water problems up until this past Spring. Got dosed at a local WA-WA. Fought the problem for 3 trips and decided to pop the sender and siphon out the water. No problems after that.

I typically start to show signs of moisture in the fuel by the end of August. End of September into October is the worst. The warm days with the cooler nights really gets the fuel shedding the extra water. Typically get a few table spoons of water a day out of the filter in that time period. Clear up once it?s starts getting colder.

Why change your filter so often? Install a vacuum gauge and change it only when you start to see a restriction. I change my filters out one a year out of habit. Have yet to change one from a restriction problem.

I typically burn anywhere from 25-30 gallons a day, seven days a week during Striper Season. Top off every morning before leaving the dock. Keeps fresh fuel in the mix.

 

[Home Cookin']

Re: Using the old gas, or diluting?

since you use a greater volume than I, you turn yours over often enough during the season--I'd like to but I have this job thing that gets in the way... (Truthfully, last summer and fall the crappy WX was always on the weekends!) But we have the same question, the low fuel use Jan-March. However, you let your tank sit half full in that time and I kept mine full, so I have more 3 month old gas to burn.
You're right about the condensation not being as bad in the winter; maybe I could try that next year, but I think you and I agree to keep it full in the summer.


I use the "big blue" filters (separator) so I can't drain them like a Racor, so I switched mine at 75 hours last year but plan to go to 50 from now on. Cheap insurance IMO.

I've done OK with my local Wawa. I have to haul it myself. Within sight of my pier is a marina but it is known (by the local mechanics) to have too much water in it. Bummer.

This boat is new (to me) last year so this is my first over-winter; the other small boats aren't an issue.

Thanks for the input. Good luck fishing; your temps are getting up? We were at 46 Sunday.

 

[Texasmark]

Re: Using the old gas, or diluting?

I'd keep doing what you are doing also. It's what I do and Stabil and Sea Foam are on my shelf too. I use the Starbrite in my farm diesel tank because of the enzymes.

Mark

 

[ChrisNCarrie]

Re: Using the old gas, or diluting?

We recently bought a boat that sat for a year. It had a little more than 3/4 tank of gas in it. He did put fuel stablizer in it, but we knew we had to get it out. We took it out a few weeks ago, but topped it off first. We also put seafoam in and ran it but only used up about half a tank. Last weekend we took it out and ran it without topping off. It is now a bit over quarter tank. Should we use up that last bit of gas, then fill up, or go ahead and fill up now?
-Carrie

 

[Fl_Richard]

Re: Using the old gas, or diluting?

Chris - It depends on your usage. If your not using the boat for four months fill'r up

 

[Home Cookin']

Re: Using the old gas, or diluting?

Chris if you got away with running that much of the old gas you are probably OK as long as you dilute it now with fresh. I'd change your seperator now, though, since it may have caught all the water from the old tank. However, sometimes the gunk shows up later.
The stuff at the bottom of an old tank can be pretty bad, so while it's down you might sample it from the sending unit hatch.
Keep your new fuel treated. keep in mind that if fuel goes bad, treatnig it won't restore it.In wamr weather you want to keep it topped off. The point of my OP was whether while it's still cool is it better to run out the old gas v. keeping it full.

Happy boating in your new boat and welcome to iboats!

 

[dingbat]

Re: Using the old gas, or diluting?

I use the "big blue" filters (separator) so I can't drain them like a Racor, so I switched mine at 75 hours last year but plan to go to 50 from now on. Cheap insurance IMO.

I've done OK with my local Wawa. I have to haul it myself. Within sight of my pier is a marina but it is known (by the local mechanics) to have too much water in it. Bummer.

This boat is new (to me) last year so this is my first over-winter; the other small boats aren't an issue.

Thanks for the input. Good luck fishing; your temps are getting up? We were at 46 Sunday.

Do yourself a favor and replace your filter with a Racor with a drain. My piece of mind comes from being able to check for, and drain, any water that had accumulated before I leave the dock. In the long run it's a lot cheaper than changing filters on a schedule.

The fish are here. The first osprey was seen over the weekend. The fish don't care about the water temps this time of year. Feeding opportunities. The yellow perch spawn is almost done and the white perch will move in shortly. The shad will be hot in heavy in the next 10 days or so. Boat goes in the water this weekend.

 

[Texasmark]

Re: Using the old gas, or diluting?

I agree on being able to see if you have any water. I store diesel for my tractors up to 2 years. I have a water absorbing filter in the delivery line with a transparent housing and a drain. I don't need to worry about what's going on, I can see it. Sleep better at night.......diesels hate water.

Mark

 

[Home Cookin']

Re: Using the old gas, or diluting?

I might, but I don't ahve a good place for it. The previous owner had a racor mounted in the splashwell, but it was too tight to get to the drain on the bottom. The "clear plastic" bowl isn't clear, and I didn't like the looks, the exposure to the sun and to the salt (moored year round). So since I had to move it, I moved the mount to inside the stern compartment, where I can't see the bottom anyway, and went with the big blue.
It's my understanding that they also filter out the gunk, so don't you need to change the can anyway?

 

[achris]

Re: Using the old gas, or diluting?

Chris,

Not sure of your engine... Think by the sounds of reading that it's a 4 stroke (correct me of I'm wrong, again)...Straight petrol will last around a year before anything bad happens.... Diesel will last a couple of years, but 2 stroke mix (oil already mixed) has a life of about 6 months, less in warmer weather...

Using and adding to top off the tank is a very good idea. One of the biggest contributors to water in the fuel is tanks that are left part filled... as the temperature drops the fuel volume decreases, and the air contracts, drawing in 'fresh' (water-laden) air. When the moisture in the 'new' air hits the fuel the water drops out of it because petrol is hygroscopic. As the temperature then starts to rise again the (now drier) air is pushed out of the tank.... Ready the cycle to repeat with new, moisture laden air.... It doesn't take very long to suck up a gallon of water....

Chris..........

 

[Cricket Too]

Re: Using the old gas, or diluting?

It's great that you are aware enough about maintaining your boat to think about this, a lot of people aren't, but I think this gas situation is getting a little overthunk. You don't have "old" or "bad" gas in your tank, so you really have nothing to worry about. Just because it has sat for 2 or 3 months doesn't mean it's old, it's still perfectly fine.

Just go out and use your boat normally. You are already up on your filter/separator maintenance and treating the Ethanol in the fuel, so you are good there.

Honestly it sounds like your putting way too much effort into the gas even during the season when it's being used. Just fill it when it needs to be filled, use some Startron to treat the Ethanol while it sits, and use the boat normally.

In 30 something years of owning and working on boats professionally, I have never once constantly maintained a full tank all season long or even filled a tank for storage for that matter. I usually have my tanks 1/2 - 3/4 full during the season and only fill them if I'm going on a longer trip that I need the fuel for. During the winter I store it with whatever is in there, usually about 1/2 -3/4 as that is where they usually are, and double treat them with Startron.

If you are going to store for extended periods of time, like a year or more, than obviously you should just drain your tank.

Also the "diluting" the tank with fresh gas is really not that, if it's only 2 or 3 months, it's still fresh gas, so you are just adding more fresh gas. If you did have "old" gas (older than say a year), then "diluting" with fresh gas doesn't freshen anything up, it just makes the fresh gas more stale, not the opposite.

 

[dingbat]

Re: Using the old gas, or diluting?

Also the "diluting" the tank with fresh gas is really not that, if it's only 2 or 3 months, it's still fresh gas, so you are just adding more fresh gas. If you did have "old" gas (older than say a year), then "diluting" with fresh gas doesn't freshen anything up, it just makes the fresh gas more stale, not the opposite.

You're not diluting the fuel per say. Your diluting the water content of the fuel. One gallon of ?wet? fuel plus one gallon of fresh, "dry" fuel, equals 2 gallons of half as wet fuel.

 

[Cricket Too]

Re: Using the old gas, or diluting?

Ahh well that's not a bad point, although I'd highly doubt that 2 or 3 months old gas has that much water in it.

 

[tav]

Re: Using the old gas, or diluting?

what if you stable the crap out of it.

 

[Home Cookin']

Re: Using the old gas, or diluting?

cricket I don't disagree with you but I've been fighting the ethanol poison for the past couple of years, as have other boaters around here, and all the marine mechanics I know. Also, while I respect your 30 years professional experience, only being able to buy gas @ 10% ethanol is a relatively new issue for boating. I've scrapped enough boat trips, paddled home and written enough checks that I probably do overthink it. But an ounce of prevention, as the old saying goes, is even more relevant today!

Now there's this guy from Minnesota who frequently says the whole ethanol thing is made up. But he's using it where there are two seasons: winter and fourth of July. Ifeel certain the hot humid South is a whole 'nother thing (but I know you get your share of it in August on the schlong).

 

[cribber]

Re: Using the old gas, or diluting?

We boat all year here in central Florida and I've only put blended fuel in our boat since that is what's available at the pump. After every trip out we top off the tank so we don't have to deal with filling it up or running out of fuel on the water. Never had an issue with ethanol eating up the seals so far. Keep your fuel fresh and if it needs to sit for a few months then add Stabil or Seafoam to keep the moisture away from ruining a good day out.

 

[Cricket Too]

Re: Using the old gas, or diluting?

Home Cookin, trust me I have been battling Ethanol as well, it's been the only choice that we've had since about 2003 or so. But I have found that most of the problems with it are due to the stripping of crap off of old fuel tanks and lines and gumming up filters, carbs, injectors, etc.. I have seen very few instances of Ethanol becoming saturated with water from sitting in a half full tank for 2-4 months.

I have seen some tanks get fouled due to sitting during the summer months in the water, but the two times that I did see that, I came to find out the boats were dropped in the water in April and when the people never used them once over the season, and then they pulled them out in November, the fuel was bad. That is an extreme circumstance though, and the biggest issue was the phase separation due to the fuel being untreated. These cases were people, who I'm sure you can guess, think they have to do zero maintenance to their boats, and then wonder why they have problems.

There is plenty of humidity here, though not as bad as VA, but from May-Oct, we see quite a bit of humidity as we are on an island sticking 120 miles out into the Atlantic. So in extreme circumstances the humidity does cause excess water and phase separation in the summer, but if you don't use your boat for that long you are asking for all kinds of trouble anyway.

You seem to use yours quite a bit, so I wouldn't worry all that much about keeping your tanks topped off after every single trip, just always put StarTron in and you will be safe.

On a side note, are you able to flush your outboard out when the boat is on a mooring?