FMF 4.1 RCT repacking tip request

Related:
Create New Tag

6/10/2018 11:55 PM

Hi Fellows,

My FMF RCT muffler needs repacking.
While dissassembling this bad boy yesterday, I noticed a metal fabric pressed/welded on the inner pipe as you can see below :

Photo
Photo

Should I remove this metal fabric or not ? I really want to clean all carbon deposit on the inner pipe, the bike is loud as hell. I am afraid not being able to put it back correctly since it seems pressed...

If I do not remove it, can I warm this metal fabric with blow torch to burn all carbon residue ?
Any suggestion with the packing material to reinstall ? Stick with FMF original stuff ?

Thank you guys !

|

6/11/2018 4:49 AM

Is there blockage on the inner pipe? I’ve never had to clean that out. Just leave that metal wrap and use the new packing, should be all it needs.

|

6/11/2018 5:00 AM

Leave it on. Wrap your choice around the outside.

|

6/11/2018 5:20 AM

CarlinoJoeVideo wrote:

Is there blockage on the inner pipe? I’ve never had to clean that out. Just leave that metal wrap and use the new packing, ...more

By lighting the inner pipe, I can see many holes obstructed with carbon residue...
That's why I'd like to remove this metal whool but I think my packing will burn faster if I cannot put it back like it is.

|

11/9/2018 4:25 AM

Quick update on the repacking.

I kept the metal whool on the inner holed pipe and packed with FMF packing kit, strictly followed the advises from FMF.
Bike is quite loud, it was 117DB at the tech inspection during my last race and officials almost clipped me for the day...

I'll remove this whool, clean the holed pipe and wire it back.
Any advise regarding that ?

|

11/9/2018 3:25 PM

Use the spark arrester insert it’ll silence it a few decibels. You could run a hone thru the pipe to remove most of the carbon

|

11/10/2018 2:52 AM
Edited Date/Time: 11/10/2018 2:57 AM

I have no real advice to you but i'll tell you my experience with FMF and sound problems.

I had the 4.1 (stainless steel) system on my 2014 SXF 450 and there was no way that i was able to get it under the sound requirements in the Finnish races (FIM rules). I tried everything to get it under the limit but i had to go back to the stock pipe.

A friend of mine that only rides for fun got the titanium 4.1 system for his 2018 YZF 450 and the moment i heard the bike i said to him that there is absolutely no way that he would pass the sound tests in a race with that exhaust. I have never heard a louder bike in my life.

|

Current fleet of two wheeled vehicles:
- Yamaha YZ450F 2020
- Suzuki GSX-R 600 K7 track spec
- Canyon Sender CF 8.0 2018 Downhill
- White GX Pro 20 Gravel

11/12/2018 5:38 PM

Motofinne wrote:

I have no real advice to you but i'll tell you my experience with FMF and sound problems.

I had the 4.1 (stainless steel) ...more

You need to hear a Kx250f. Mine was loud stock and with the 4.1 it was crazy loud.

|