I'm not sure if the gearing is the same on the XTZ but i found the following with my XTZ.

If you want to accelerate at all you must be above 3000 rpm. Below this and the engine will bang and bounce all over the place

Mine will bimble along at 2500 rpm in top eaisly but if i want to speed up i have to change down.

Make sure that you are in thr right gear for a corner. Changing down mid corner is not great as it can upset the bike..try to avoid it unitl you are happy with the gears and revs.

I've never really needed to go above 5500 rpm but it will do more. I stick between 3000 and 4500 most of the time on the road and this give me a top speed of around 75mph.

But the most important thing for me on my XTZ was the 3000 rpm thing. Below that and you aint getting much...on 3k and she will pull happlily.

Now others may be along to tell you that the gearing is different on yours so you will have to work out what 3k on an XTZ equates to on yours but you will get the idea.

Go play.

Mike