recently had a few problems with my Zed with a poor idle.changed the belts and the idle control valve and its now sorted that out.however, it will now only rev to 2500 at the most, even foot to floor.it sounds a bit spluttery when doing this.anyone know why its limited to this?and what i'd need to change to sort it.i've checked around and the MAF sensor seems to be a common thing to change in this situation but any extra info would be appreciated.thanks Dave