WT-9 carb, also good WT-499 and WT197.
www.ch-ignitions.com
Your ZDZ ignition should be OK. Set the ignition timing for 30deg BTDC.
The factory muffler is quiet but reduces power by 800-1000 rpm.
Also check to see if your engine has a decomression hole just above the muffler. If it does plug it.