When designing the PowerCore 4, FMF looked at their top of the line products to deliver race-inspired performance at an economical price. The end result is a quality muffler with improved torque, increased horsepower and rugged durability all at a price that wont break the bank. Overall increase in power and torque. Durable stainless steel and aluminum construction. Space Age internal packing material for maximum longevity. Hi-Flo modular end cap. Internal shape of core uses Hi-Flo technology. Enhanced sonic evacuation provides for higher flow and increased power. Includes removable spark arrestor. Note: For closed course competition use only. NOT intended for street use. Detailed Specifications: Type: Slip-On. Configuration: Single. Construction: Aluminum. Finish: Champagne anodized. Midpipe: Stainless steel. Endcap: Stainless steel. Spark arrestor: Screen insert (included). Quiet insert: Quiet insert (sold separately). Weight: 5.3 pounds. Note: For closed course competition use only. Not intended for street use.
"I ride a 2003 yamaha raptor 660, awesome ride. Awhile back i purchased the fmf power core 4 for my 2002 yz 426, i was impressed with the overall sound and low end power that was increased by installing this exhaust system. The decision was made that i also wanted this exhaust system on my raptor, so i purchased it from motosport.com. It Arrived at my door a day early and i was stoked that i had a new part to install on my toy. The overall look and ease of installation of the fmf powercore 4 was impressive. It took me a total of 15 min to install. All the parts and instructions were included in the package with easy to follow directions. If you install this slip on exhaust from a stock exhaust you will be satisfied immediatly once you fire up your ride. The sound is smooth, crisp and rewarding the first time you take off. This overall product was a good buy and i would recommend it to any one wanting added performance and good sound from their atv or bike. I have this system on all my toys and am extremely pleased with FMF all around."