Made a carbon fiber silencer and end cap for the YZ. The stock weight was 1224gm for the stock aluminum parts and the CF parts are 742gm saving 482gm, over a pound. Cost includes the epoxy, Kevlar and CF materials to make the silencer and also the mold. I have made several end caps since then for about $10 each since the mold is already made.
09/14/19 - After five years the silencer needs some work. The carbon fiber mounts have rubbed through the canister in a couple places. A little patching will fix it up but I'm planning to design a new one in carbon fiber with mounts that are built into the canister.