Yes pump 87 octane gas is pretty much crap in 30 days.
Many places here in Michigan sell what they call rec gas
, supposed to be non ethnol.
You will pay more for it how ever and I still do not recommend leaveing it in the sleds tank all summer.
I used to when it was easier to remove the air boxes like the let the sled run then spray Marvel Mystery oil in the carbs throats till the engine died. Coated the cylinders and all the stuff inside of the carb(s).
Find pure gas AKA rec gas in your area.
I like to run this type of gass all the time as much as possiable. Never know when you may have got the sled ready and rode it then have an accident and can't ride for a while.