Colin NSR wrote:I'm no expert, and hence this could be bollox, but I thought that the front and rear cylinders have different heat rated spark plugs simply because in addition to liquid cooling, the front cylinder receives significantly more additional air cooling than the rear. Obviously much more cool air will hit the front cylinder, whereas the rear is tucked away and hence will run hotter, therefore a plug which draws more heat will be in the rear.

Yes that is correct the front cylinder will run Cooler than the rear (But not just because it is more open the rear cylinder is buried in the centre of the bike ),But the extra heat at the rear cylinder is normally taken care of by running a larger Main Jet as the atomised fuel actually cools the cylinder (well the piston crown more to the point) this is why SAFE jetting is rich as this will keep the cylinder cooler and reduce the risk of a seizure.

While I'm talking about the rear cylinder - There is a little duct which runs from the lower left side scoop on my fairing, and disappears of under the tank. Is this to get some fresh cool air to the rear cylinder - I assume it isn't ram-air, what is it