Use 5% max nitro, Bisson makes a really nice sport muffler for it, it's a dykes ringed engine so don't let it go lean, keep it a little rich to break in and keep it below 5,000 for about twenty minutes.
I use a regular Fox Gold Post Idle bar plug in mine. It is a smooth runner. It may be a little rich in the midrange until the low speed needle is right.