I have a stock pipe on a 2005 z400. I took the spark arestor off to clean it. In side of the pipe ahead of the spark arester is a wadd of grey yarn like insulation. Is this normal? Do you repack these stock pipes? They look completely welded together so I am not sure how you would do anything to them.

 

yes thats normal and you can re-pack it if you want. just go to your local powersports place and ask for regular 4 stroke packing. you will probably wanna wear gloves. wrap it around the core as many times as you can. it should be a snug fit when it's all put back together.

 

oh wait a minute i just realized you said "ahead of the spark arrester". well, that may be a problem. think you could get some pics?

 

On the z400 it is a stock pipe that looks to be completely welded together. It does look like you can take it apart like an aftermarket pipe. I was if anyone has experience repacking a stock pipe like this?