I bought a 07 400ex with an HMF exhaust system already on it. Apparently it is really loud and is not liked by my neighbors. I was looking at the HMF silent core to insert when I am riding around my house. Has or does anybody use this and how much quieter is this? Is it worth it or should I just go back to the stock pipe and rejet losing power??

 

Dont go back to the stock pipe. Contact HMF and ask them what they recommend you to use.

 

Get the quiet core...it's about 20 bucks and will quiet it down substantially. It will not be as quiet as stock, but unless you get a silencer, no performance aftermarket pipe is quieter than stock

 

oh yeah...you won't have any noticeable loss of power by adding the quiet core.

AND...thanks for taking steps to avoid being "that guy"...you know, the one who spoils it for all of us

 

What does that mean???

 

it refers to the dolt who thinks more noise = more power, and runs a crappy and loud exhaust system that splits everyones ears and upsets the neighbors...the ones that are so loud you can hear them above everyone else riding at an ATV park.

What that does is cause irritated neighboring land owners to take atv park owners to court, or get sections of public land closed off to atv riders

We as riders will be the cause of our own undoing...Loud bikes, obnoxious and/or helmetless riders, trash left on the ground, torn up land (NOT treading lightly)...those all serve as justification to judges/administrators to close down/fine owners of the places we have left to ride...no paranoia here, it's REALITY. Check with the BLM, or even look at this site...riding areas are being closed down every month.

So......DON'T be that guy who spoils it for all of us

 

Amen!!!!!!!!

 

I can agree with that.

 

Right now HMF is having a deal where you can trade in that old can for a newer design. It could probably use a good repacking and the quiet core will help, but the sport series HMF are still 99-100dB usually. The newer ones are supposed to be much quieter.

 

Yes I do not want to be "that guy" and since I have to live next to my neighbors (even though we are out in the country) I don't want to create a war! Being civil is smarter than being on a loud quad for sure. When I was riding through the woods, people said it sounded like a race car echoing through the trees and that they could feel it! Not what I want and Im sure not what they want. I read that the DB level on my pipe is 105 and with the quiet core it is 94db and that stock is 89. To me that is way better but as far as it actually sounding quieter , I don't know. I have contacted HMF and I am waiting for their response. I would not mind trading either I suppose so long as I keep my power.