99-19 YAMAHA YZ250: FMF Gnarly 2-Stroke Pipe The FMF Gnarly pipe focuses on increasing the lower RPM horsepower and torque to get you out of the toughest terrain. When looking to add 4-stroke tractor like torque to your 2-stroke and you need a pipe to withstand the harsh elements, this is the pipe for you.All pipes are electro-nickel plated for a non-chip finish that will not discolor.Nickel plating is an FMF trade Not intended for street use.