FMF Powercore 4 pipes and decibal limits

I was told today by a Ranger that the FMF Powercore 4 pipe I am running on my 650 is over the 96 decibal California limit.. (not the bike i was riding today, btw). I'm going on the Sheetiron 300 in May and am told I need to be in compliance. I visited the FMF website, but saw nothing that would confirm that they make a tip that will bring it into limits. Anyone with experience on this matter?

I think the Power Core 4 is a 98db muffler. I've been told that you can hush it up by updating it to the more recent Q version by replacing a baffle and a turned down tip. Contact Chris Finley at FMF and ask about part# 045022 (this # is for the 600R/650L - don't know if your is the same or not) FMF BULKHEAD/ENDCAP UPGRADE KIT P-CORE4 "Q" $40.95 :)


What did you find out?? give us an update.

one order to FMF and ~ $70 later..

I called FMF.. I didn't get ahold of Chris.. I ordered the Powercore4 Quiet Core Insert - $24.99 and the Premiere Muffler Packing - $37.99. The sales girl i talked to said the Quiet Core Insert brought the sound down anywhere from 1 to 3 decibals, and that the Premier Packing was better for sound attenuation and longevity than their other packings. The Ranger had said the insert alone would bring the bike into conformity, but I figure the bike has 3+ years on it and why not change the packing at the same time. Should be here by Friday. I'll let you know what i find out after the ride, May 22, 23. I also have the PowerBomb header, which they say is better for sound.


If you can post a picture when you're done that would be way cool. :)

The other day I took off my PowerCore modular end cap and couldn't really see a way to "repack" or get to the "Packing". I did notice two wields. Is this a relativly straight forward process or is is tricky on the FMF PCIV?


I haven't repacked mine yet but I think you need to remove the four front allen screws (around the circumference of the muffler)and slide it off towards the rear. There are instructions at the FMF site under tech support (I didn't see either of our bikes listed, but there were instructions for the XR400 - probably close enough in this case).

This is the FMF instructions for my muffler, which appears to be the same as yours. At the bottom it talks about re-packing the muffler, and refers to the allen bolts at the FRONT of the muffler, and says to NOT remove the endcap. My parts are in, and my son and I will be re-doing our mufflers tomorrow night, will keep you posted and attach pics. (if I remember to take my camera)

Also, I see you are using the dualstar mirrors. How do you like them? I just ordered some for my bike.

take care,

John :)

Well, we installed the kits and the sheetiron 300 is over now. The day we installed the quiet cores and new packing, I remembered to bring the beer and forgot the camera, go figure.

The quiet cores and packing did a remarkable job of quieting the bikes, and I don't notice much power loss, though my son claims he does. The Sheetiron 300 was a great ride, btw. Take care :thumbsup:

Thanks for the update bloosman! :thumbsup:

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