Andy wrote:You really want to check the power jets before any high speed runs if you are using otherwise stock jetting.

I've just had a very interesting chat with a tuner, powerjets, according to them, have nothing to do with top end, especially as they are so small (#70, 75 etc..). He said that it is not even used in anything over 1/4 throttle, and its there just for when you snap the throttle open at low revs to give a better responce.

Have booked my bike in with them so will have a good chat with them about it then.