Super easy to install. And even though its a quiet pipe. It sounds great. Much louder than stock. Power was night and day in difference
FMF Q4 Hex Spark Arrestor Slip-On Exhaust
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I have 2 small annoyances with this product
1. The muffler sticks out much farther than stock and contacts my plastics. Nothing has melted yet though
2. My stock clamp is too large for this pipe. I didn't buy my bike new so it is possible that it wasn't a stock clamp but I doubt it.
Other than that, it's a nice piece, looks well made, quieter than stock.
Motorsport are the best
Bought one few months ago and i couldn't be happier. Sounds great, looks nice, and definitely with more power the bike. Recommended!
Wanting to trail ride my CRF450R requires that I have a spark arrested pipe, which is what drove my purchase for an aftermarket exhaust. After some research I decided to go with the FMF Q4 slip-on. Reason being that it has both a spark arrestor as well as it is <96dB. Racing in AMA D37 we have to pass sound test, which this pipe accomplishes.
Overall Rating: 5 stars. I am very happy with this pipe.
Ease of Installation: 5 stars. Tools required were an 8mm, 10mm, 12mm sockets, ratchet, ratchet extension, torque wrench, and silicone sealant. You could get away without a torque wrench or silicone sealant but I always work by the book.
Style: 5 stars. This pipe fits perfect. The location of the muffler is perfect under the fender. All gaps are even and the muffler to header fitment is absolutely flush and perfect. At first I thought the pipe was damaged when I received it due to a strange crease about 5 inches back from the header, almost exactly 180° from the mid pipe bolt mount but after calling FMF to confirm before starting the installation I was informed this crease is "the factory bend to clearance the frame" and once installed I could see its purpose. When you unbox this pipe dont let this crease scare you like it did me!
Performance and Power: Both 5 stars. The pipe sounds great. Not stupid loud but still with that sweet 450 bark I like to hear. Powerwise, it is just a muffler, there may be a slight increase but it isn't life changing. I don't care what pipe you run, none will give you unbelievable HP gains but the real benefit is the reduced weight. This muffler is quite a bit lighter.
Overall, if you are looking for a muffler with a spark arrestor, a sweet exhaust note, quality construction, made in the USA, and outstanding fitment I HIGHLY recommend this one.
Really sounds great. Not too loud cruising around town. Pretty loud when your getting on it hard. I don't see it being a problem with the police. I would buy again!
Performs as described.
Note: factory clamp to header will need to be replaced (too small). Acceptable replacement clamp: Moose Racing 1861-0683 1.94-2.12 inch ID.
It would be nice if the clamp was included with the kit.
excellent to ran on your bike. I have a kx 450f it worked good
I bought this for my 2013 KX450F. It was so easy to put on!! I was looking to lower the DB's down a bit, it did the job. I was also looking for a pipe to ride with on state land so it needed to have a spark arrestor. This pipe was well worth the money. Took 5 min to install.
The FMF Q4 is designed for quiet forest approved riding. The 4.1 series is the newest and will give you more power than the Q4.
If you are going with just the slip-on no remapping will be required. If you pair it with the mega bomb or a header along those lines it will still run good but remapping would certainly help.
It is an insert held in by one screw in the end cap.