ok the z400 has 11.3;1 compression what octane should you use? I know in cars if you want to use street gas (pump gas) in a high performance motor 10.5:1 is pretty much the highest you can safely go without detonation. I mean a quad motor is pretty much the same concept as a car engine.

 

Nope all you need to run is 87 octane. Any of the 87, 89, 91, 93 will work fine but over that is a COMPLETE waste of money and very overkill for the stock engine.