You can run 87,89, or 93 octane in it. You may, that is may, get better cleaning with the 93 octane fuel. The engine was designed to run on 87 so there is not any good chance it will run any better on the higher octane fuel. About the only difference is your wallet will be a little lighter.
Now on the other hand, if you have an engine that is designed to run on 93 and you put in 87, you will have an engine that pings, possible predetonation, and probably will not run as designed due to the fuel.
Now I have been in a pinch before where I could not get premium fuel for the Harley and have put in regular. It did not die or run terrible. It kept on going and I put in some premium fuel down the road. But I could not really tell much difference between the two fuels and it is not really a really high performance engine.
Let us know what you do and what you think