carb cleaner did nothing to the exterior of the head.<br /><br />neither did any conventional cleaner.<br /><br />was recommended i use Yamaha Genuine Parts Combustion Chamber Cleaner. it did a fantastic job on the aluminum parts, but apparently the heads are made from some other kind of alloy.<br /><br />i uploaded this pic to a buddys page to show the motor and how the colors are different between the cylinder and the head.<br /><br />
http://img.photobucket.com/albums/v671/ ... tor.jpg<br /><br />i decided to live with it instead of spending more money.