If it's at 30 degrees while idling, you have too much advance. Shoot for 15 degrees at around 1000 rpms. As you back the timing off, the idle speed might drop; if so, readjust it to 1000 rpms, then back the timing down again.

Repeat as necessary until the timing is something like 15-17 while the engine is idling. If it refuses to stay running once set, the carbs are likely too rich.

You can then start the engine and begin leaning out the carbs (and again, readjusting the idle speed along the way) until you get a good idle with the timing set. By now, it will have been running long enough that you can dial in the timing once and for good.

THEN (finally!) you can actually tune the carbs.

Best,

Cameron
444,122SC
Rose City