If you are using heli fuel they smoke alot.

The way to temp test the engine is to put your finger on the backplate, if its cold you can go leaner, if its warm but you can hold your finger there atleast 3 seconds its about right, if its too hot to hold your finger there its too lean.

Fly around then land quickly and check it right away, a bit of hovering and or a few laps around the field is good enough if you aren't into aerobatics yet.