The klx300 spark arrestor is deep in the can, there is an endcap on it that has 2 8mm bolts, remove the endcap and you have a fairly free flowing exhaust and its a little lighter than stock, not alot, but makes a decent performance gain.

Here's a vid without the endcap

On the 2nd pass to the left all shifts were at 10K.

 

fyi, the BG system with quiet core ISNT quiet!!!

 

My HMF w/Quite core was pretty good from the start but still a bit too loud for my requirements.
After much thought a discussions with NVH guys, I modified my quiet core with very favorable results.
What I did was:
1) remove the quiet core
2) fabricated a plug to fit the leading end or inlet of the quiet caore insert.
3) weld the plug in place
4) calculated the area of the I.D. of the quiet core, and a drill size of suitable sizeto drill 40 holes on 4 planes into the quite core the would be equal to or greater then the original area of the core.
5)drill the holes and clean up the burrs
6) reassemble your modified core.

The mod to the core was easy to do and worked really well for taking away the harshness.

What this does is break-Down and redirect the harshsound wave w/o sacrificing restrictioncausing loss of preformance.

Now beforeeveryone starts complaning about pictures, NO I do not have anynor can take them easily asmy bike is parked for the winter at my cottage.

I will get photo'swhen Iopen the place up in spring.

DJF