ok i've got a z400 and when i top it out the motor pings noticeably....not loud but i still hear it...the performance is good it just has that stupid ping...any suggestions???? it's all stock and i'm running 93 octane

 

You said pinging. Are you saying you are sure it is preignition knocking??? Is your engine fairly new?? New engines can make funny noises that go away later. Your fuel is 93 octane, but is it FRESH??? I mix 1:5 with race gas, just to be sure I keep the octane up, even after the fuel has been is storage a while.

 

the motor is about 2 weeks old...i'm not good at pointing out sounds all i know is that i hear a knock or pinging sound whatever you want to call it

 

If you're topped out, that means the rev limiter is kicking in and the ignition is temporarily cut out. Ipso facto, it could be raw fuel igniting within your exhaust pipe.