Trials Australia Forums

I just did the repacking of the Beta Rev 50 for the first time (a regular occurence on the KTMs!!!).

The silencer casing is riveted to inlet and outlet end caps. A baffle tube runs between the two. So I...

1. Drilled out the rivets carefully

2. Tapped the holes in the end caps 6mm

3. Made the holes in the casing slightly larger to help line up the end caps in the casing at re-assembly time.

4. Pulled out the old packing which was dripping with oil - errr yuch...

5. Wrapped my favourite Bradford Insulation Rockwool around the baffle tube. Held in place with paper masking tape.

6. Re-assembled with short 6mm stainless cap head screws.

Bingo...nice looking job, with serviceable silencer and better running bike.

I also did the muffler packing on the Sherco 50 yesterday. The original packing was still in there and not too bad although near the baffle tube it was soaking.
I put the usual wrapping of rockwool in - and the engine note was then a bit a bit sweeter. Can't say I noticed any performance improvement.

Question for KTMSprocket...why not fibreglass insulation?.
It's the same looking stuff that comes standard in the Beta end silencers. I've always used rolled up insulation batt and it works fine.

I've done some crude backyard experiments and read the may threads on our MX forums.

Rockwool basically doesn't melt or burn. If you take a piece and try to ignite it, it won't. If you add a little petrol, the petrol will burn and then go out. If you soak it and ignite you will find it will 'burn'.

The pink bats will burn/melt and leave a mess. I haven't tried this with 'proper' exhaust packing. So, as the material is both hot and mixed with a small amount of accelerant, I went for the Rockwool. As it is SOOOOO cheap, it is well worth it.

As the little 50cc two strokers spew oil out the back when run around slowly, changing the packing is a fairly important thing to do to keep the bike running nicely. It also mops up the goop!!!!

Remember: A few mates can chip in $10 each and get a sheet or two each and that will do alot of packing!!!!