FMF Racing Powercore 2 Shorty Aluminum Muffler w/Stainless End Cap for Yamaha YZ80 93-01/YZ85 02-24/YZ85LW 22-24FMF Powercore 2 Shorty Silencer Yamaha YZ80 YZ85 Based on the performance proven platform of the Powercore 2 Silencer, FMF created the Powercore 2 Shorty Silencer, which utilizes a shorter aluminum canister and inner core. This design decreases the amount of back pressure in the muffler, which on a 2 stroke will increase throttle response and low to mid range power. If you spend most of your time riding on tight tracks and trails, the Powercore 2