I'm hoping someone can answer some basic questions regarding the spark arrestor on my bike. The '78 parts list shows a different muffler/arrestor than what I have. I think what I have is from a later year (1979-1981/2?). It is stamped #F15-1041 on the plate.
First, what is the big spring that's welded inside the arrestor for (see pic)? I assume at one time there were muffler packing "cartridges" that were available that were loaded in and held by the compressed spring. Is that correct? To pack the muffler I'm just going to wrap fiberglass sheet several times around the perforated core tube attached to the end cap and then use wire to tie it tightly to the tube. Any reason not to do it that way? I need to do something because this bike is real noisy as is.
Second, this arrestor doesn't seem to have a screen. I believe the units for US bikes had a screen inside the end cap. This one doesn't. Has anyone added a screen to this type of arrestor? Is there a retrofit of some kind that anyone can recommend?
Thanks, and if this post should be in another forum let me know.


First, what is the big spring that's welded inside the arrestor for (see pic)? I assume at one time there were muffler packing "cartridges" that were available that were loaded in and held by the compressed spring. Is that correct? To pack the muffler I'm just going to wrap fiberglass sheet several times around the perforated core tube attached to the end cap and then use wire to tie it tightly to the tube. Any reason not to do it that way? I need to do something because this bike is real noisy as is.
Second, this arrestor doesn't seem to have a screen. I believe the units for US bikes had a screen inside the end cap. This one doesn't. Has anyone added a screen to this type of arrestor? Is there a retrofit of some kind that anyone can recommend?
Thanks, and if this post should be in another forum let me know.

