I was invited to this site to let everbody know about the POWER TECH4 exhaust system for the Z400 and KFX400. You can get a Slip-On or the full system.The systems are made from T-304 polished stainless steel and never need to be repacked. There are no rivets, screws, bolts or flanges to leak or fall out. The sound is fantastic with a deep rich tone and not snappy or raspy. Dyno test have resulted in a 5 hp gain with a 147 jet. No air box mods were done. With air box mods and jetting additional hp is very attainable. Email for more information or pics. from now until the end of the year all prices are reduced 10% and FREE shipping.