250-500cc Silencer re-pack help 2012 Wr300.

I hope someone out there has been through this already. I started the process of re-packing my stock '12 WR 300 silencer and not being familiar with this task, I ran into a little snag. After pulling the exhaust stinger end out, I could not remove the inner pipe. The packing came out easy enough, but the pipe did not budge. Is it supposed to come out? If it does not, re-packing will be next to impossible. I have not tried to screw it out and do not want to bugger it up. I have to be missing something here. It can't be this complicated.

My 2011 WR250 had screws on both ends and also had rivets I had to drill out. But I am not 100% sure they have the same silencers.

I don't have the stock one on mine, but I had to remove the inlet side for a repack.

There is an o-ring on each end that seals it up pretty good. Makes removal tough but with a rubber mallet & patience it can be done. Some remove o-rings & use RTV during re-assembly, I kept them just b-cuz.

I have both ends out and the packing is removed. The O-rings made it a little tough, but I managed. What about the inner pipe that the packing wraps around? If it does not come out, how in the heck do you re-wrap it? If I drill out the rivets, do the guts come out? Has anyone ever used the pink FMF High Performance packing? It would be simple enough if you can just fill it up with that.

Yeah I am pretty sure you have to drill out the rivets. I just ran a M6x1.0 tap in the holes and put a bolt back in them for next time, when I put it back together. This will get it completely apart. Like I said I have a 2011 250. I cant think of a 2stroke I ever had that I did not have to drill out rivets, so Ill bet it is that way.

I drilled mine out and re-riveted.

I have a 12 CR144 and just the endcap comes off, the core stays with the body and inlet cap which is all welded together. It is still possible to repack it. The stock packing is formed and just slips in but they are garbage at best. The best repack option IMO is Silent Sport long-strand packing. It is also private-labeled by MSR and Moose I think. Anyway, you just separate the stuff and use any long tool (screwdriver) to load it down the silencer. Don't pack it super tight, but enough so there is no way it will settle or bunch to one end.

I took my inner core baffel out and took a propane torch to it. Once you cook all junk off of it, take a wire brush to it so all the little holes are exposed and air can pass through it. I repacked mine with the Pink Shreded FMF material. Repack it 'loose'. The sound level on mind dropped 30%.

My inner pipe doesn't come out (or at least I don't take it out). I keep a couple paper towel tubes in the garage, wrap fresh packing around the tube, with a bit of masking tape holding it around it. Slide the paper towel wrapped tube into the canister, then slide just the tube out. Works like a charm

Thanks for the input and tips. Brad_O is on to something. I tried the same thing with a section of PVC pipe, but it was a little too big. The paper towel tube sounds like the ticket. Thanks again!

That may work ok but there seems to be some confusion on the function of the perforated core..... The holes are NOT there for air/exhaust to go through and into the packing. They are there for soundwaves to easily disperse past the core and into the packing, the goal is to NOT let any exhaust gas leave the core and give it a straight shot out of the silencer. This is achieved by packing the material semi-tight against the core. If you are using a paper roll to aid in installation, there is no way the packing is adequately packed in there, against the core. ANY open spaces hurt flow by causing turbulence as exhaust gasses circulate through the holes. It also will destroy and "blow out" the packing faster, which turns into a vicious cycle and a silencer that needs repacking after 3-5 hours of hard (rev) use. The only good option for those type silencers is muzzle-loading long-strand packing like silentsport in there. The end result will be superior in performance, sound reduction, and will last way longer. I stopped messing with those short-strand woven mats a long time ago, they're garbage and blow out fast (short strands get sucked right through). The only plus is they are cheap, but pennywise dollar dumb, have to pack it four times as often to maintain performance of a SS-packed silencer, and it will never absorb soundwaves as well. Anyway.....