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Drilling baffle

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I know this has been discussed a few times and I have searched but can't seem to find a definitive answer.

'06 kx450 loud as hell - standard muffler have repacked but am considering drilling a few more holes in baffle to allow more gas to circulate through packing.

I know a few people have done this - did it work?

It's not a major job will take maybe 30mins tops my problem is will it work or will it make the bike louder?

Don't really want to go with another muffler and have tried a DB Dawg but didn't like what it did to the jetting,gave me a horrible surge at constant throttle that i just couldn't jet out no matter what I tried.

Pulled the DB Dawg out bike ran perfect again!

Most of my riding is open trail/woods etc mostly on private land so noise is not a "legal" problem.

But 2-3 hrs of riding with that noise just wears me out,its fine until I'm hard on the gas - the top end rasp is shocking.

I have the baffle sitting on the bench with a drill beside it, was about to attack it but thought I better check first.

Thanks for your input:ride:

Great forum

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I ended up disassembling (sp?) the silencer and checking it out.

I ended up drilling some of the existing holes a little larger and then driling about 150 more holes in the inner pipe and then repacking the silencer. I blew a 93 this past weekend!

Here's a pic of the holes I drilled out larger.

258966963_27vg6-M.jpg

Here's a pic when I was halfway done drilling the additional holes.

258965475_fAEUK-M.jpg

Here's what it looks like from the rear!

263436110_qTu4o-L.jpg

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Sweet thanks for the reply,Am walking to garage now with drill in hand......:)

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I ended up disassembling (sp?) the silencer and checking it out.

I ended up drilling some of the existing holes a little larger and then driling about 150 more holes in the inner pipe and then repacking the silencer. I blew a 93 this past weekend

Good work. Surely you need to repack it more often?

fzrnut, maybe you could make a muffler exit turn down, like the PMB part. Aim the noise at the ground. I never have any problem with jetting for the db-dawg. I just went one clip leaner on the needle and down one size (to 172) on the main. Ran fine. Don't use it any more though, since for quiet running, I have a wr450f muffler with Ti midpipe, which is no heavier than stock, and flows better than the db-dawg and is very quiet. Love it. I'm like you, I feel much less rider fatigue without the noise. My stock muffler is very loud.

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Thanks numroe - keeping my eyes open for a wr450 muffler as we speak,any particular year I should be looking for?

Also heard that '09 KX450 muffler runs at about 93db stock so thats another possibility should be a few around soon...:)

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Thanks numroe - keeping my eyes open for a wr450 muffler as we speak,any particular year I should be looking for?
06 or later WR450F muffler. IE. any of the alum ones. The WR250F might have to same muffler too, but I'm not certain.

btw: I modified the final exit pipe in my WR muffler. A little larger diam, but I have the bell mouth entry positioned differently than Yam did it. Hard to explain and needs pics. I seemed to have got lucky since it works really well in terms of performance and not much louder than a stock WR except for the KX induction noise. No spark arrestor screen obviously.

Also heard that '09 KX450 muffler runs at about 93db stock so thats another possibility should be a few around soon...:)
93dB. Couldn't be. Even the Euro/Aus spec bike (smaller muffler exit hole) has to be louder than 93.

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Thanks numroe - keeping my eyes open for a wr450 muffler as we speak,any particular year I should be looking for?

Also heard that '09 KX450 muffler runs at about 93db stock so thats another possibility should be a few around soon...:)

According to MXA the '09 tests at 95.2 db, thanks to electronic trickery, but that in the real-world, it's the loudest bike on the track.

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Just get a KLX450's muffler.
That'd be a practical and easy solution, but how to get some weight out of that thing? It would probably feel the same as a small bag of cement strapped to the rear fender.

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My stock silencer had a couple of layer of metal net wrapped around the inner pipe,I think this to make the packing last longer.But it also makes it louder,remove it and repack the silencer more often to quiet it down.The 06 inner tube is full of holes,its only the later kxf that for some stupid reason only has holes on half the inner tube.

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My stock silencer had a couple of layer of metal net wrapped around the inner pipe,I think this to make the packing last longer.But it also makes it louder,remove it and repack the silencer more often to quiet it down.The 06 inner tube is full of holes,its only the later kxf that for some stupid reason only has holes on half the inner tube
.

Yeah mine had holes all the way down the baffle - I just enlarged a percentage of them.

I spent quite a while looking at that metal net,came to the conclusion that it would stop a lot of gas getting to the packing hence making it louder almost like a straight pipe.

It's still in there mainly because I was worried that without it I would blow my packing out pretty fast.

Thanks for the great info and advice.

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