Buying an 05 kawi 360p 4x4-question

[MgOnZo700]

Not sure if this is supposed to be in the tech corner section.
I went to look at a used 05 4x4 360 prairie yesterday in my area, it seemed as if it were in very good condition but when revved it sounds as if it doesn't come back to full idle.Is this normal?, is there anything else I should look out for on a 05?
it doesn't return to a normal slow idle? at a faster than normal idle it will bang when changing gear.