Gasoline Question. - Maxum Boat Owners Club

Smithbrother · 03-30-2011, 08:28 AM

I bought the 21' boat last summerin late august with a full gas tank, went thru half a tank before winterizing. Now that spring is here the question is should I just fill it and go or do I need an additive? If I need something to put in the tank prior to filling it what should I use and where do I get it.

Thanks,
Dave

seapuppy · 03-30-2011, 02:08 PM

you didn't treat the gas and fill it when you laid it up for winter????......that maybe a big problem.....you probably have alot of water condensation in there....what I'd do is get some water absorbtion gas treatment stuff......then fill the tank...take the boat out for a drive on the trailer to mix it all up....then put it in the water and start it....you may dodge a bullet and not have to drain the tank and start over....after you run the stuff thru the tank..change the filters and put fresh gas in the tank...
on a side note....never ever store your boat with half a tank..try and keep the tank full at all times...this will decrease the chance of water being absorbed into the tank thru condensation.....

SP

ss3964spd · 03-30-2011, 03:11 PM

Treated gas vs non, full tank vs not. These have been ongoing debates and I don't think I've read any conclusive proof to support either argument for one method over another, except from the purveyors of the additive products. From all the reading I've done on the additive subject there is one important point to bring forth; there are no products that actually absorb water from gas. My understanding is that all they do is break down the water into smaller drops so it mixes with the gas and can be ingested by the engine with little concern.

In other words; add one cup of water to one gallon of gas and look at it. The water doesn't mix - it all stays together. If the fuel pump were to suck up that big blob of water and deliver it to the engine, at best the engine will run ruff or stall, at worst it will hydro lock and end your day/season. Now, add in the appropriate amount of additive. The water blob is broken up - disbursed throughout the gallon. The engine likely isn't even going to notice.

Food for thought - although perhaps not apples to apples. My chain saw had been stored in my shed for at least a year. No additive whatsoever and with about 1/2 tank of gas - E10 from the corner station. Pulled it out 2 weekends ago, switch on, choke on, and it started on the 3rd pull and ran without complaint.

If it were me I would do what SP said; pour in some of the additive and then drive the boat around for a while on its trailer to mix the stuff into the existing gasoline. I understand the logic of then topping off the tank to improve the gas to water ratio but, if the engine has any gripes about the gas quality after you've done that, you'll then be pumping out a full tank opposed to a half a tank. If it were me, I'd run it on the treated 1/2 tank.

Mine got stored this winter with 1/2 tank, but treated. Won't be too long before I know how she runs.

Respectfully submitted,

Dan

seapuppy · 03-30-2011, 05:01 PM

Dan
that's certainly one way..but the full tank will disperse the water into a more deluted state...this will hopefully burn off easier....more gas...less parts per million in the gas....

SP

biggerseagar · 03-30-2011, 06:40 PM

I would add to all this..........if you don't have one is to add a water seperation filter system to the gas line too.

I have always used a gas treatment product like sta-bil or sea foam in the fall lay-up and then also in the spring first couple of fill-ups add some gas treatment and had very good luck.

I have read also that for a recreational boat size gas tank that the condensation that would actually occur in a 75 gallon or less gas tank if all these safe guards are done will not be enough to damage anything, but better save than sorry I say!

I have had very good luck to the half full method in the gas tank and plenty of gas treatment in the tanks. Put it in the gas maybe a week before you put the boat up and run it thought the system. Sta-bil offers a E10 formula which is green in color and the regular red for regular gas.

Whatever you decide please do one of these methods talked about with treating your gas supply before putting your boat up for the winter. You will save alot of headaches and money by following this advise!

Roger

ss3964spd · 03-30-2011, 06:46 PM

Could not agree more Steve.

If my boat had a really large gas tank that was 1/2 full I'd probably opt for filling the tank. But since mine holds only 70G, and since I'm insanely curious about the whole E10 and condensation debates, and given that I've never had an issue with starting/running my gas powered tools on old gas, I'd be willing to take the gamble just to find out. But that's just my screwy way of thinking. LOL

jeffmeans · 03-30-2011, 07:02 PM

I'm a BIG believer in SeaFoam. Not sure WHAT it was that got into my fuel last year (I suspect early season gas from the marina, or 10% ethenal from the street pump before I launched Endless Summer) but the SeaFoam stuff worked miracles. Within an hour or two of dispensing it she ran on plane, no sputters, no coughing... ran like a top. And last season I stored mine practically empty (10 gallons or so in a 102 gallon tank) but it was treated (with what I don't know---I suspect it was Sta-Bil, but I don't know).

I too am very curious about the condensation issue, or perhaps the culprit is indeed the E-10 crap they're dispensing now... who knows. All I know is SeaFoam solved the problem.

Smithbrother · 03-31-2011, 09:08 AM

Thank you all, I had a professional Marina witerize the boat for me. I don't know if they put additive in for me. I see pink stuff in the water tank so I know they put something in there at least. I will give them a call later this week. Thanks again. Dave

shrew · 03-31-2011, 03:55 PM

SS:

Regarding your chainsaw.....I have noticed that my 4 stroke motors tend to be more senstive to older gas than my 2 strokes. I'm personally curious about how premixed fuels come into play here. Certainly small engines like my lawnmower seem to have less of an issue, though my outboard and snowblower hate old gas, oddly enough. My motorcycle and boat in general get very cranky with old fuel. The weedwhacker and chainsaw will start after sitting for 2 years. They smoke a ton on old gas, but they do run.

I've always wondered about this.

ss3964spd · 03-31-2011, 08:22 PM

I wondered the same thing Shrew, but since oil mixes completely with gas I'm hard pressed to understand how it would make a difference in regards to water in the gas, or any "stabilization" benefits.

Before my oldest son started driving, my old 1984 F150 honey-do truck would sit for 2, 3, sometimes 4 months without being started. But it never failed to start and run, which did little to provide any justification to get rid of it. Boy I hated that truck.