Pipe looks great, fit was excellent, and really inproved the power on my Z 400. Put this on with an FMF Power Bomb header. Made a huge difference with the improved torque and horsepower. I didn't order the quiet core, but it came with one in the box. Good thing, because it needs it. It's loud with it in, a really nice deep sound, but without it, an obobnoxiusly loud and crisp sound. I'm sure a lot of riders would like it though, just not me. The quiet core also has a spark arrestor on it for trail riding. After serveral rides with this pipe, it still looks great. One reason I went with FMF is because they stood behind there header on my KTM 690 SMC. A weld broke on the header and they repaired it free of charge even though I had no receipt, bought it used and was out of warranty. They not only repaired the weld, they cleaned off surface rust, and put the uniformed brush marks back in the whole header and it looked like new. Also gave me three headshield mounting clamps. All for free. You don't get service like that much anymore.
I put this on my '07 YFZ and notice a decent amount of difference in the power band. I eneded up getting the anodized blue (I have the Yamaha blue) and looks great! One minor down fall, I got a wash plug with the exhaust but no exhaust springs. There only an extra $5, so no biggy. I didn't order the wash plug, but it was in the box with the exhaust. Overall, looks great and sounds even better!!!
I matched this muffler with the powerbomb header on a 08 YZ450F and everything was great. It took about ten minutes to put on, gave it a great sound, and totally changed the powerband. It filled in all the gaps in the rev range and it made the bike easier to ride. Power wise I could say that it doesn't matter what gear your in, the bike does the same thing in all of them. A great exhaust.
I recently bought this FMF pipe for my Yamaha YFZ 450 atv. I had some issues with another FMF pipe I purchased where the canister ripped apart. I am not sure how this one will last in comparison to the power core 4 muffler, but so far so good. I like the power output of this muffler. It seems to have good torque out of the hole, and more top end power than the power core 4. If you are looking for a good pipe, and don't mind servicing it more frequently, it is a great all around pipe.
We race enduros and this pipe produces great power but does not pass the 96 db needed it runs at about 106 db which is very loud for Michigan woods racing. But if your on the track its a fantastic pipe with loads of power!
The muffler didn't come with midpipe or springs shown. It didn't fit my KTM 525. I ordered a header and midpipe directly from FMF, via phone, as I really wanted this muffler. The header didn't fit either. I verified all part numbers with FMF directly. Weeks of back and forth with FMF, via email, via phone, via my dealer, pics sent. All with ZERO resolution. I mean I never got an answer nor an offer for return/replace, I had to tell them I was sending it back. Returned it all and purchased a complete Akropovic exhaust. The Akro fit right, sounds awesome and makes great power. Stay away from FMF, they have poor quality control, poor support, and poor products.
Dennis Kirk is the best though. Speedy, easy return for a full refund!