Try to get the TT instructions on how to run in an ABC type engine. Do not attempt to find an 'idle' until the engine has a hour or so running, the carb does not have an 'idle adjust' control, just mid range and full power mixture controls. The idle speed will depend on the prop fitted, and will change with different props. It will be what it is. Do not rely on the 'electric finger', TT engines start within 3 flicks if there is nothing wrong. More than that and you need to start looking at fuel and plugs, cause something is wrong. Invest in a prop balancer and use it. Make sure that your engine mounting screws/bolts are tight. There should be no metal bits leaving the exhaust, otherwise something is wrong. Any dark staining in the exhaust muck, muffler/engine joint or around any engine bolts is a sign of fretting aluminium, and you need to check bolt tightness. Find your local club, get help, these are good engines, but you need to treat them with care (as with all engines, of course) and given that care will outlast your airframe.
Evan, WB #12.