guys I am out in California so the highest octane I can run in my 300 Promax an my 280 is 91 octane fuel both of my motors on both of my boats have been sitting for a couple months when should I start getting worried about my octane level is going down? how long is the lifespan of the fuel I know after it sits so long I shouldn't run it But what is too long? thank you for your time fellas
91 octane. ......how long ?
- Thread starter smiley88
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Bobalouie
Active Member
If the fuel has ethanol, about 3-4 weeks and you can see it start to separate out the alcohol and water, which can cause you problems. If it is ethanol free, then it lasts for about 3 months or so. Better to be safe than sorry though, I would pump the tanks down as far as possible and put fresh fuel in. Run the old stuff in your lawnmower. IMHO, the big worry is not the octane going down, it is the water separating out of the fuel.
Pumping the tanks out if they have been sitting for a couple months is a lot cheaper than repairing a powerhead.
Pumping the tanks out if they have been sitting for a couple months is a lot cheaper than repairing a powerhead.
chad202
Well-Known Member
I read a lot about the ethanol fuel
seperation. My boat has sat for 4-6 months several times and I run ethanol fuel. Before using I would get a jar and pump some fuel out and let sit. I've never seen it two phases in the jar but I still pump out majority of it and fill with fresh fuel. I have theory's why is doesn't phase out, at least down here in south Louisiana. I've being I never store my boat with a full tank. Always leave a big vapor space. With the heat down hear and the vapor pressure of fuel my tank is always venting which keeps the outside air from coming in. In cold climates it's probably different. I know people that disconnect the vent hose and block it off so outside air can't get it which is where the moisture comes from. Just my opinion.
seperation. My boat has sat for 4-6 months several times and I run ethanol fuel. Before using I would get a jar and pump some fuel out and let sit. I've never seen it two phases in the jar but I still pump out majority of it and fill with fresh fuel. I have theory's why is doesn't phase out, at least down here in south Louisiana. I've being I never store my boat with a full tank. Always leave a big vapor space. With the heat down hear and the vapor pressure of fuel my tank is always venting which keeps the outside air from coming in. In cold climates it's probably different. I know people that disconnect the vent hose and block it off so outside air can't get it which is where the moisture comes from. Just my opinion.
So it's safe to say to just drain the tanks ..my next question is can i just drain the tank and refill for next time out or should I pull the gas line hose that goes to the motor and turn on fuel pump to pump out every last drop ?
michael j giesler
Active Member
This is how i have done it with my boats get a about some fuel hose get a old fashioned primer bumb pump it all out put a gallon or two of race gas or av in it turn on on your fuel pump let about a half gallon or so run threw the system then shut it down till your ready to use that way i always hated using your fuel pump to run your tank dry because you may pick up crap at the bottom of your tank that will wreck fuel pumps injectors and regulators i know it's way overkill but it always work for me
whipper
Well-Known Member
I have this little shaker hose with a ball bearing at the end i stick it in the tank shake it and it siphons the gas and fill up a big jug with the old fuel. Theirs lots of places if you don't use it that will dispose of it for free for obvious reasons. They wont pay ya for it though.. :] I just make sure i drain enough so the new gas is more in the tank. On a promax i would drain the VST tank also. Thats the first shot of gas your motor gets on start up. Mines been sitting month and a half now. If you use aces you dont have to worry about it. Its probably a good thing to run. I used to run it. But hard to get up hear now.
Sounds good to me I planned on siphon and everything out of the tank and just running the fuel pump and let it get everything out of the fuel pump and lines attached also but like stated above don't want some of the bottom crap from the tank coming through the fuel pump..thanks for your time guys..
GotMyAlly
Well-Known Member
What's the difference in mixing ethanol and non-ethanol in the tank vs what they do at the refinery?
Bobalouie
Active Member
While you are in there messing around with pumping the fuel out, add a 100 micron filter between the tank and the pump, that way your pump will be protected, and you can pump out the tank with the fuel pump. Thats what I used to do.
ROBERT CROSS
Well-Known Member
I use 91 e-free with Aces, store with siphoned tank just for Shitz & 
.
.Lotus 50
Well-Known Member
I follow the BRP Etec recommendations on all my motors. Run some BRP 2+4 fuel stabilizer through the engine, and store with a full tank with stabilizer. I have to buy the 2+4 for the Etec warranty, so it gets used in everything. BRP obviously doesn't make it, but they do set the specifications, which means something. We are lucky in southern/central Ontario and we can buy ethanol free fuel.
I don't understand loss of octane over time. The light stuff should evaporate first, which would raise the octane and leave gum/varnish behind in the injectors.
I don't understand loss of octane over time. The light stuff should evaporate first, which would raise the octane and leave gum/varnish behind in the injectors.
I understand guys but my problem is I didn't plan on boat sitting like this ...so I didn't prepare for adding anything or putting stabilizers in therefor it's been sitting with nothing but ethenol crap gas.now that it has been sitting I'm trying to figure out exactly what to do step by step without any damage down the road.just want to take all necessary precautions. .
GotMyAlly
Well-Known Member
Pump it out and pour it in the lawnmower, car, etc.
Bobalouie
Active Member
+1