2 year old fuel - Drain or keep over winter?

[hellz_wings]

I have a 1998 Seadoo Speedster (with twin 787's). I've had this gas (91 octane, non ethanol) in the boat since August 2019 now, and the tank is about half full. We put a marine fuel stabilizer in the gas tank with the fuel back in August 2019 before storing it then and it has not run since (I'm in the process of re-doing engines, carbs, new fuel pump, etc.) I am bringing the boat back into storage as is, with the work unfinished and will finish it all up in spring *(April/May) of next year.. My question is, what should I do with the fuel in there now? Can I just fill it up to the top with more 91 octane non-ethanol fuel and put more fuel stabilizer in there and should I do this NOW or leave it as is and do it in the spring time, or do I need to drain it NOW and put brand new fuel and stabilizer? I'd rather not have to drain it now as time is limited at the moment and I need to bring it Friday to storage, but will do it if I absolutely need to (ie: remove the fuel baffle again and siphon it out with a manual siphon pump that I have, hopefully the hose is long enough to get it all out!). Thanks in advance for the help!!

 

[hellz_wings]

Just to add: can i leave as is and drain it in the springtime next year or will the gas gunk up the tank or something? It’s plastic so it’s not like it can rust or anything but a half tank of old gas shouldn’t do anything bad if it just sits there right? Obviously I will drain and re-fill before starting the boats.

 

[mikidymac]

You can drain in the spring. I would use a little at a time in my vehicles. Even with non-ethanol and stabilizer 12 months is about max.

 

[hellz_wings]

awesome, thanks man! I'll put this bad boy in storage and in the spring drain and re-fill the gas tank and oil tank and re-fill with 91 octane and XPS synthetic in the oil tank (the oil tank had a little bit of blue oil in there which was some other type, so I siphoned out as much as I could but couldn't get the remaining out the bottom, and I filled it up with XPS, but now that I am changing oil lines, filters, etc. I might as well drain fully, replace with XPS and bleed the system to be sure all the old unknown blue oil is gone.

 

[mikidymac]

Yes, mixing oil can cause them to gel and block the oil injection, ruining the engine.

No reason to run 91, your boat requires 87.

 

[mike1117]

FWIW Get rid of it asap. I'm dealing with that right now re a 96 xp that I rebuilt carbs for last spring. Kids filled their skii with old fuel and fouled their summer fun. Just finished a complete tank removal and line flush along with winterizing it. As for disposal that's another topic.

 

[Jtamaro]

There is mixed info about this..
probably better to drain in case, but to be honest I have left the minimal fuel in over the winter break and I fill the tank with fresh fuel at the start of summer and it’s never been an issue for me

 

[mike1117]

This wasn't my ski it was a customer's, kids filled it with old fuel they had laying around. Spent today adding fresh rec fuel, priming engine and finally running for an hour to sort out remaining bad fuel in carbs. For the customer's enjoyment I hope his fuel issues will be trouble free next year. I enjoy the troubleshooting and repairs.

 

[hellz_wings]

Im prob gonna leave it there and in the spring siphon it out from where the fuel baffle goes in, thru the fill hole is pretty tricky to get it all the way down to the bottom. Anyone have any tricks on how to empty completely aside from taking out the tank which is pretty much impossible without removing engines lol

 

[mike1117]

Removing the tank wasn't a big deal on the xp I worked on. Siphoned as much as I could thru fill, removed fuel pickup ass'y along with fuel selector complete with fuel lines. Removed tank tie down straps and pulled tank thru front access opening. It was the perfect time to replace the remaining gray fuel lines as well. Engine was undisturbed. Reass'y was straightforward.

 

[bigtexan99]

Funny story, I had a full tank of 2 year old fuel in my boat once and I put an ad on Craigslist for "free old fuel". Some guy showed up with gas tanks and siphoned it out. No idea what he wanted it for.

 

[hellz_wings]

Hey guys, about that time to drain the fuel and get this thing runnin. I am looking a siphonS on amazon and there are a few. It’s a 98 speedster jetboat, not a jetski so the gas tank is huge on this boat. Any ideas on how to empty this?

Also, 87 octane contains some ethanol no? Thats no good for our engines right?

 

[mikidymac]

87 octane has nothing to do with ethanol or not, you can find it with or without depending on the state.

 

[hellz_wings]

87 octane has nothing to do with ethanol or not, you can find it with or without depending on the state

I think here in Montreal Canada all 87 "may contain up to 10%" ethanol. I always put 91 in any 2 stroke motor over here.

 

[mikidymac]

Wasting money with 91 as it is not needed in these engines and will do absolutely nothing. Only one that needs it is the 951 DI.

 

[hellz_wings]

I think it’s more the ethanol factor that worries me - if i can find 87 with no ethanol i’ll def get that, otherwise i’ll stick to 91

 

[mikidymac]

Honestly the ethanol thing is overblown. We have it here and I have had no issues in any of my skis, motorcycles or small engines but I do us Sta-Bil.

 

[2StrokeBoatGuy]

This wasn't my ski it was a customer's, kids filled it with old fuel they had laying around. Spent today adding fresh rec fuel, priming engine and finally running for an hour to sort out remaining bad fuel in carbs. For the customer's enjoyment I hope his fuel issues will be trouble free next year. I enjoy the troubleshooting and repairs.

I just put a new 787 in my 96 challenger and I have fuel that is about 8 to 9 months old, but it us not ethanol free, I wanted to crank it over just to be sure boat was good, but I couldn't get my see so beep, long story short, I ordered a new starter relay and installed it and realized the issue was a ground wire on second battery which is needed for spark, previous owner set it up with extra battery behind the steering wheel under the basket.

should i get this fuel out before i break this engine in with break in oil.