Thinking about getting a slip on

What slip on do you guys recommend? I'm thinkin eithe power core 4 or Q4. Thanks

What slip on do you guys recommend? I'm thinkin eithe power core 4 or Q4. Thanks

Get a full system from 07 -09 yz and install the PMB end cap. Best bang for your buck IMHO. If you have to have FMF I like the Q4 as they are a bit quieter.

If you like louder, get the powercore 4. You can always get the quiet insert for it to make it like the Q4. If you buy the Q4, you can't make it louder.

The WR has a smaller headpipe than a YZ so a YZ full system is a good idea. I bought a DR. D and it works pretty good.

search the threads

Edited by n16ht5

well, if yer planin on having your slip under your skirt, just make sure it don't show...

anyway, my buddy cut down his stock WR pipe and installed a Pro Moto Billet tip with screen and it actually looks, and sounds pretty good. just a thought anyway...

What is it with people liking loud? I just bought a 07 WR 450F a couple of weeks ago. It has a 2 Bros full M7 system. Way to loud for me. Tried a P4 insert with spark arrestor which didn't seem to quiet it at all and just made the annoying chirping sound worse. I ordered a full Q4 powerbomb system like I have on my son's 09 KLX 250S, which I really like.

I need to play around with the m7 insert a little more. There's a pretty good gap between the muffler and the carbon fiber end cap. I guess the P4 isn't meant to fit with the spark arrestor installed.

Does anyone know if the 2 Bros header will fit and work properly with the Q4? Didn't know if it would, so I ordered the powerbomb just in case.

The 2 Bros Header is about as big around all the way through, as the powerbomb header for the KLX 250 is at mid-pipe.

Edited by Kamp

Is anyone running the GYTR insert? If so, how happy with it have you been and what have you noticed? I'm really looking for more power and better sound. I removed the baffle but I still don't feel like it sounds all that good.

I've run the GYTR insert in my WR426 with the stock exhaust can. It runs pretty well, and usually blows about 96 dB. Its got way better low end that the stock pea-shooter that came with my bike. I currently use a FMF Q which blows less than 94 dB (which is our limit here in Michigan) and I think the FMF has marked power improvements everywhere over the stock can with GYTR tip, and its quieter too.

If I were to rank the power from lowest to highest from what I have used, this is how it would be: stock, stock can with Vortip (White Bros), stock with GYTR, FMF Q. I ran the stock can one day without any tip, and I would honestly say it was almost identical to the FMF Q, but was louder than hell. My vote would be for the FMF Q. Quiet with good sound characteristics, and excellent power.

Do you know what a stock freshly packed YZ silencer sound level is?

I will be getting sound tested in Sept. I'm hoping that the YZ w/ PMB passes 96, but I don't think it will. I think it is more like 98-99db.

07 yzf is the quietest YZ pipe out there ASAIK. Very quiet, probably 95db. with a spacer it fits the stock head pipe

If you install the GYTR insert do you have to re-jet the bike?

If you install the GYTR insert do you have to re-jet the bike?

With ANY change in air or fuel flow you should rejet the bike. Open up the airbox so more air can flow, rejet. Add an exhaust that has better airflow, rejet. ALWAYS a good idea.

the 07 pipe is a better bet for the money. tons lighter too. if you have $180 to spend get lexx

the price is right, is the lexx any good? anybody know how it compares to FMF, not Q series, in power and sound?

the mounting strap sucks but otherwise the quality is on par with FMF. great power, I like the spark arrestor much better than the FMF type, less restrictive. Comes with a few different tips... super duper quiet (88db), medium (94db), and loud (98db)

best pipe I have tried yet.. I love being able to swap tips in just a minute or two when I need to be quiet.

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