My bike has an older Pro Circuit 304 Silencer on it and I would bet that it has been a long while since it's been re-packed.

It has been done before though because the housing has screws holding it in place. New silencers are held together with rivets and you have to drill them out to repack. Someone already did this on this silencer... which made my task a little easier. Just take out the 4 screws and pull the end off.

It's a bit of a nasty job as you can see. Oil spooge everywhere... I may be running a tad rich. I'll watch the plug closely for the next month or so while the weather warms up but I'm pretty confident that this mess is just the result of years of use without re-packing.

The core was actually pretty clean with no blockage.

After wrapping the new pack around the core you just re-insert it into the silencer and bolt back up. It was pretty easy to do. BTW, I used the MSR 2-Stroke Pack and it cost about 6 bucks at the local Honda Dealership. I also sealed the end of the canister with Honda's High Temp Silicone Sealer.