Making 87 octane higher

[West94]

My question is what is the best way to make 87 octane 91 or better? The lake marina i'm at only has 87 and my boat likes higher just runs and starts better after hot. Will adding 2 stroke oil help higher the boiling point and if so how much per gallon?

[justgary]

Octane booster.  Theoretically, it's just toluene, but it may be safer to buy it as a specific octane booster product.