I have the thunder tiger 39 it will run for about 5 minn. an then shut down?

It maybe overheating, what are your needles set at?

try 3 turns out for the main. The idle needle is the important one, the main needle does very littel on that engine, it is not like most other engines. a lot of folks do a modification to the idle needle to get more rich midrange and leaner idle (grind about 1mm of the end to more of a point) works great. Love the TT heli, but i don't think they have figured out how to make a good 30 size engine yet.

Annother possible culprit could be that you are running head speed too low and applying too much pitch to get into the air and putting extra strain on the engine. Blade pitch should be aroud 5.5 at hover and head speed should be in the 1750- 1800 RPM range. hang in there it gets a lot better once you get used to it.

thank you for that info

Man, don't know why people don't like the TT 39. I had one on my 30 before I sold it and it never missed. Sounds to me like you are too lean.

I have seen on TT run good while another run bad, their inconsistent.