Fuel preparation for winterization

[WildCatFan54]

So , like many other members, I am preparing for a "fact of life" ! Winter is rapidly approaching and my days on the lake are getting fewer. Here is the decision I have and would like the recommendation of others in the same situation ? My boat lives on a lift year round. In late October or early November I typically start it one last time (each engine )on the lift for 30-45 seconds to blow out all excess water from the cooling system. Drain and add RV antifreeze to the fresh water shower tank. I remove both batteries and store them in my house for the offseason. I take off the bimini and bring it home for cleaning and fabric protection application. Then cover on the lift with the factory shipping cover That leaves the gas tank ? I understand that condensation forms easier in an empty / half full tank. However , would it be better to fill up the tank with marina gas (who knows how long it has been in their holding tanks ) , then add stabilizer knowing I'm not going to run the engines again until next April. That stabilized gas could be anywhere from 6-9 months old by then. OR , run it down to almost empty for the winter then add fresh gas in the spring ? Thoughts please ?

 

[captainhook]

The general recommendation I’ve always seen is to fill the tank before winterization due to moisture purposes. I would put in some Stabil and fill the tank before storing it. The ride back would sufficiently mix the Stabil and get it into the engines.

 

[WildCatFan54]

thanks , I always have but something about having OLD gas starting out the next season just doesn't appeal to me . I guess the question really is , how good a job does Stabil really do in preserving octane rating in the gas ?

 

[captainhook]

I run my boat every year so I’ve not had any issues with 8ish month old gas using Stabil.

Several years ago I did have to drain the fuel tank in my SeaDoo once when it sat (with Stabil) for 2 or 3 years after I had a couple of kids. If I recall correctly, it did run, just poorly. That required 93 octane so it was probably more sensitive.

I doubt you’d have any issues with the marina fuel even if it’s a few months old for a single offseason

 

[WildCatFan54]

Good to hear. NO more kids for me so long as I'm vertical and not six foot under next spring will be operating the boat ?? Going to keep doing it the same way as years past.

 

[2kwik4u]

Mine lives in the garage, however I do have a fuel process.

Local gas station has "Recreation Gas" that is 90 octane and 0% alcohol. Don't care about the octane, but the no alcohol is important. I'll run the boat for an hour or so to get the alcohol free fuel in there, then shut her down for the season.

Sadly, I filled up this morning for our last ride this afternoon stupid fall!

 

[212s]

Always add the proper ratio of fuel stabilizer, fill the tank, then run the engines for several minutes in the water to get the stabilizer into the fuel injector lines. If you don't, then you will have stale gas in the lines trying to start it in the spring. Stabilizer is good for at least a year with new gas. Make sure you use "marine" stabilizer that can absorb any moisture in the tank.

For Yamaha engines - DO NOT RUN THE ENGINES without cooling water for more than 15 seconds. They can overheat and cause issues or seize. This is straight from the manual. You just need to start and rev the engines twice up to 3000-4000rpm to clear out the water from the waterbox mufflers. Just a couple of "varoom - varoom" on the lift is fine.

Here in Canada we usually can boat till the end of September, and can fire her up again end of April after the cold breaks. That's about seven months of storage and we've never had an issue with fuel - she starts and runs perfectly in the spring even with older carb engines.

 

[212s]

Sadly, I filled up this morning for our last ride this afternoon stupid fall!

We're not boating this weekend as it's too cold, below 50 is too cool for us, but next weekend we expect it will be back up into the high 60's and possibly the 70's and will be able to get out again. The last couple of times out on the boat we add stabilizer in case we get caught with a cold snap, this way the gas is already treated and in the lines.

 

[seanmclean]

Stabil is fine for seasonal storage. Add it to your tank after your last outing, fill it up on the way home, and run it a little bit to circulate (you'll likely be doing this for your pre-winter oil change anyway).

 

[Canuckjetboater]

@WildCatFan54 .....definitely marine gas or 91 to 94 octane as there will be no ethanol to phase separate and yes you can also use use a fuel additive but not one that will attract water.

 

[Emptytemples]

I'm a believer in making sure to run the boat to get the stabil through the engine(s). Ill fill it and add fuel treatment before my last ride. Top it off with each before she is put down for the winter. I don't think running the engine to fog it, for instance, is long enough for treated fuel to work its way in. I just always thought that and could be off base. It may only take a few minutes for that fuel to work its way through the fuel hose into the engine. Having non ethanol gas is a big factor for me too most of the year. Only when really convenient do I use ethanol added fuel.