Does it fire and not run or not do anything?

RC engines are pretty simple machines. If you have fuel and a good glow plug, they will fire. Do this. Check your plug to see if it lights. Look in the air bleed hole on the front side of the carb. The screw should be half way across the hole. You may have to take your spinner off to see this. Turn your needle valve in and open it 2 turns.

Turn on your radio and open the carb, put your finger over it and choke it 3 turns. Then flip the prop over 6-8 times. Idle down. Hook up the glow plug and try to start. It should at least fire. If it does start, leave the battery hooked up until you adjust the needle valve.

Thunder Tigers usually take a long time to break in. This engine will last a long time. You just need to get the settings and the starting procedures down.

By the way, plain bearing engines are not designed to be started with an electric starter. The bearing is only designed to take forward thrust loads. Many times, using an electric starter will cause the crank pin to hit the rear cover, shaving off metal and leaving marks. Ball bearing engines will take loads in both directions.