I'm not sure what you mean by "Hard" but if it's reving high adjust your idiling screw.
it basically lets the bike work at higher revs, for example on mine it gives it unlimited revs, so it wont stop at about 6000rpm like a normal bike but just keep going, it can be bad because if the revs get too high the engine may explode
The timing is off.
it could be due to the steper motor but i suggest you take it to mechanic because no saxo has ever had a carburetor
you are stepping on the gas peddle too hard
check for vaccume leaks. this can sometimes be hard to do so take you time.
Fusion? Pulse? Revs? or my faviroute Hard Core?
Governors limit the RPM on the engine. Removing it will allow higher revs but can cause harm to your engine.
You may be pressing the gas pedal too hard
check your vacume lines by spraying them down with carburetor cleaner. if the engine revs when you spray you found the leak. also check your air flow meter it could just be dirty.
It is time for a professional car mechanic to have a look. The steering may be caused by dry joints (needs greasing), the revs may need the engine to be adjusted to run slower.
check the on/off valve the rubber inside can become brittle and fall apart clogging the fuel line.
Im assuming you mean a powerband on a 2 stroke motorcycle - when you hit the a certain level of revs an extra valve opens giving you the extra power surge that you feel on the bike.