You can try some of this
Did it have any studering or loss of power in those few days? I think symptoms show earlier but I could be wrong. Might try /r/MechanicAdvice
“Heet” in the yellow bottle from an auto parts store. $3-4
Here it is for $1.27 from amazon: HEET 28201 Gas-Line Antifreeze and Water Remover, 12 Fl oz. https://www.amazon.com/dp/B0016GXNC4/ref=cm_sw_r_cp_api_i_3jrhFbR43FQP8
You could use something like the HEET fuel treatment and run it through the bike, then put new fuel in. The better solution would be to use a transfer pump/syphon pump to drain the bad gas and put fresh fuel with a small amount of HEET in.
https://www.amazon.com/28201-Gas-Line-Antifreeze-Water-Remover/dp/B0016GXNC4
https://www.amazon.com/SWANLAKE-Gasoline-Siphone-Transfer-3-5Gallon/dp/B0B2NTW2XJ
I am an advocate for the Fancy Feast Stove. It is my first pick every time I am not near a fire ban. I have tried a lot of different "designs" of them but Skurka's really does seem to work best.
https://andrewskurka.com/how-to-make-a-fancy-feast-alcohol-stove/
I use yellow Heet and a Stanco Grease Pot.
It's a really light system (grease pot 66g stove 6g) that just works time and time again without much cost. The bigger pot is plenty for any meal I eat and works very well with the FF stove size wise. No pot stand needed and I use aluminum foil folded up for a lid and a wind screen. I have a Vargo Fuel Bottle that I use sometimes but a lot of time I just use an old 8oz apple juice bottle. I don't heat much over two cups at a time and that takes about half to one ounce of fuel.
Bad mileage could be alot of things.......I gassed up at a different station that I usually use, and didn't drive on the highway (just city).......and I panicked with bad mileage.
Then.......after running through that gas....went back to my old fill up place and used the usual gas I use......and, drove some highway miles.......and mileage went up...to where it should be.
Don't panic.
Once I put some fuel stabilizer in to prevent water .....https://www.amazon.com/28201-Gas-Line-Antifreeze-Water-Remover/dp/B0016GXNC4/ref=pd_lpo_1?pd_rd_i=B0016GXNC4&psc=1
......and it totally fucked up my mileage. Maybe the sensors activated and coded for a richer burn....don't know.
You could drive yourself nuts figuring out sudden low mileage (spark plugs, MAF sensor, O2 sensor, MAP sensor, etc).
Best thing is run a diagnostic tool on it.....and figure out why she's burning rich. It's an art form to figure out just how to use a diagnostic tool. Study up on that....you should be in the ball park with just a cheap 50$ scan tool.
Don't know what a scan tool is? Youtube. Study. Find a place to ask questions.
Best advice......is find a forum online for that engine and model......there, you will find someone who has had the same problem.
Usually, same engines have same problems.....and the crowd usually figures it out for you.
Scantool.
To properly read the diagnostics....takes an experienced mechanic who have the investment in the best scan tools.
So.......this could take alot of your time for free.....or you can take a chance on a mechanic who may or may not spend the time to properly read the diagnostic data........or you can get a mechanic that charges you the necessary 200$--400$ that they all charge for anything any time you bother them with something as mysterious as reduced gas mileage.
No matter what.....the mechanics are gonna charge you for their time, at least 75$ an hour.
So...start studying online and do your own research first.
There's plenty of forums for all cars and engines.
But ask yourself......"did you add anything to your gas"...or "did you gas up at a different station"? That happened to me.
just keep bailing and replace it with more hot water as said above, or if the gas station is still open, go get some yellow "Heet" gas line antifreeze. but scoop as much water out first.
https://www.amazon.com/28201-Gas-Line-Antifreeze-Water-Remover/dp/B0016GXNC4
Are you about ultralight, comfort, minimalist, what?
In general, my opinion on ultralight, DIY alcohol stoves is favorable. I haven't done much with them, just overnight rainbow campouts and stuff, but they've held up really well. ( http://zenstoves.net/Stoves.htm)
They take a while to boil water with the standard type of cookwear, but with a modified Heineken can, they boil in about 5 minutes or so. Great for tea, oatmeal, and heating stuff up, not so good for cooking meat, etc, but use a survival fire for that. ( https://m.youtube.com/watch?v=p7Zw5YBdZHM)
They're super easy to make, use, and refuel. Really cheap to make, literally could be free. The fuel can be anything from bathroom variety rubbing alcohol to vodka, but I've found that Heet antifreeze burns the cleanest, and pretty much everyone who makes these uses it. Make sure to get the yellow container though. The red works too, but not as well. ( http://www.amazon.com/28201-Gas-Line-Antifreeze-Water-Remover/dp/B0016GXNC4)
What's your budget? We can recommend all kinds of stuff but the light and durable stuff is not cheap. That aside, my first choice in a backpack will always be Osprey as long as they stick to their Almighty Guarantee. My second choice in backpacks would be Gregory. Neither of these two companies will let you down.
As for stoves, my highest recommendation is the Optimus Nova or the Optimus Nova Plus. The reason I recommend these particular stoves over something like the MSR Whisperlite International is the fact that the pump rod is aluminum and not plastic. You're really going to have to try to break the pump on the Novas. I have a regular Nova stove myself and it puts out plenty of heat. I've even used it as a mini forge to melt down lead for my diving weights. It kicks ass, comes with a spare parts kit, windscreen, combo wrench and cleaning tool. It doesn't come with a fuel bottle, but I don't know any liquid fuel stoves that do. All 3 stoves will run on multiple types of liquid fuels including kerosene and unleaded gasoline. They will NOT run on denatured alcohol though. I've tried it, it doesn't work.
If you know for sure that you'll be able to get isobutane canisters I would recommend something like the Optimus Elektra which comes with cooking kit, the MSR Micro Rocket if you're prefer something without a cooking kit but that also includes piezo ignition, or the Optimus Crux. Those last two stoves would be paired with something like this GSI Pinnacle Soloist cook set. To be perfectly honest though, I have 3 of these. I've had them for about 2 years now and have no complaints with them other than that their flame pattern isn't symmetrical... If you have a small cook set like the Soloist and can use isobutane, these "should" work fine.
For a sleeping bag and pad, I would recommend Big Agnes for their Big Agnes System design which removes down insulation from the bottom of the sleeping bag, where it doesn't do you any good anyway due to being compressed by your body weight. Instead that have an integrated sleeping pad pocket that allows you to put a 20 inch wide sleeping pad of your choice in the pocket for insulation. I wouldn't recommend the Neoair pad to be honest. The only real reason being that it isn't as insulating as any of these pads. You're going to want something with an R-value of at least 5 if you're camping in any sort of cold weather.