2009 Buell XB12Scg rocker cover is fastened with 4 screws. There are washers with rubber inserts under the screws. The James Gaskets kit has 8 fiber washers and 8 copper washers. There are no similar metal washers with rubber inserts in the James Gaskets set. Which washers should I use to install the rocker cover? Only fiber washers? Only copper washers? Or both fiber and copper washers sandwiched together? Also the screws have their own washer.