Re: Thunder Tiger Pro .21 Buggy Engine
I have never used thunder Tiger engines, but have not heard anything bad about them yet, except main needle jets vibrating loose. Do you have the book that came with the engine? They usually have good starting points in there instructions, It is always better to go to rich than to lean. I live over sixty miles from where I race and have to readjust my engine every time. This is just mostly the main jet and the idle setting. If your fuel is more than three months old and not stored in the optimum conditions, it will attract water and won't run worth a damn. Maby try a new glow plug.
About 2 1/2 turns on the main needle and the idle set flush with the carb body. Check for air leaks, leacky front seal, they will make tuning a nightmare, I know.
Start off with the manufacturers specs and go from there. Tuning can take time and these engines are easily affected by altitude, heat and humidity. Hope this helps.
If it ain't broke fix it till it is.