Long live 2Strokes

Im trying to get an old YB100 i have roadworthy so i can stip down my other working bike for a respray Anyway as I got it without a baffle in the silencer I tried swapping the one from my L2g into it but unfortunately it doesnt seem to quite seal the plug and it still sounds like a dirt bike. I was told to use packing with the baffle and got given a 500mm square sheet of it. So how much of this packing should I use and how do i use it? Do i just wire it on or cable tie and let let them melt in the exhaust as i was told?

G'day all, Just stumbled on in to the forum here thought I would say hi! I'm 28 and from the Sunburnt land... Adelaide, South Australia to be exact. Started my motorcycling career on Old Kawasaki GPz's but have accumulated a collection on Yamaha 2-strokes all in dire need of a little TLC. I have a habit of picking up things on their way to the wreckers and trying to give them some life again. Current shed consistes of Yamahas - 1985 RZ500 (RD500 in the US i think) 1980 DX100 1977 YB100 1975 L2G Kawakas - 1984 GPz750 (Air Cooled) 1985 GPz600R Currently the DX100 and YB are my main focus (coz they are cheapest , but also the only 2 that run under their own steam atm) but the RZ will be next on my list i think. Just cant wait to see that V4 firing again!