Jump to content
Sign in to follow this  

FMF quiet core insert

Recommended Posts

I have a FMF powercore muffler on a DRZ400S

I find it too loud for street use.

Can someone tell me the dimensions of the quiet core insert, ie, length and inside diameter.

Has anyone tried this option and did it reduce the decibels by a noticable amount

Thanks

Share this post


Link to post
Share on other sites

I have a FMF power core on my YZ250F. I installed the quiet core and it made a significant reduction in noise. Dont know db, but guess it would be close to 96. I think you would get similar results with the DRZ.

Share this post


Link to post
Share on other sites

I'm thinking of making my own as I dont live in US

just need to know the dimensions

original powercore end pipe is around 1 3/8"diameter

I am guessing the quiet core is 3/4 to 1" inside diameter ??

Share this post


Link to post
Share on other sites

Length= 5 7/8" I.D.= 1 1/4". End cap diameter wont matter core goes down inside silencer. Mine is for a YZ250F but I believe FMF only makes one quite core to fit all the Power Core 4 models.

It made it very quite but also killed the power. Although I did not rejet as I was just using for a couple rides. It probably would have ran better if I went leaner on the main jet.

Share this post


Link to post
Share on other sites

Vet

Thanks a lot for that info

I found a picture of a quiet core in FMF's pdf catalogue.

It looks like a tube welded to an oval plate which attaches to the rear of the muffler with 3 socket-head screws

Is that the same as yours?.

With the picture and the dimensions you gave me I should be able to get one made here in Cambodia for a couple of bucks

Share this post


Link to post
Share on other sites

Vet

Another question if you dont mind

Is the tube on the quiet core insert completely hollow or is there something inside it that helps reduce noise.

Just wondering how a 1 1/4" ID hollow tube would reduce noise

Thanks

Share this post


Link to post
Share on other sites

Its totally hollow. I think the length has a lot of effect on the noise. Try it, I would think you will get noticable decrease in noise. The Power core is way loud, about 102db or so. Let me know how it works.

Share this post


Link to post
Share on other sites

I think it will get you to about 96 db or around there, to me that is plenty quite. If your want like stock or around 93db, I dont think its going to happen.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×