IMHO it's your E-free gas doing that for ya.
All I use on OPE and boat. Never a issue with it.
Today's prices since going up this year even higher is now 4.79 a gal.
Must be nice. 4.79 here up .30 from last year.90 octane "REC GAS" e-free is 3.49 at local Circle K. Sometimes they run out and I go to a BP station that has 89 e-free. They are usually .20-.30 higher