Dumb newbie question coming up! I've use the search function, read many posts and come to the conclusion that the LSN on the TT39 should be between 3-4 turns out as a starting point. But I have a question on how you measure this? I can think of 3 methods;
1. Fully open the carb, screw the LSN until you get to the end of the thread, back out 3-4 turns.
2. Fully close the carb (no opening), screw the LSN until it seats on the HSN (perhaps?), back out 3-4 turns.
3. Set carb at approximate throttle idle (very small opening), Screw in the LSN and back out 3-4 turns.
I have 2 TT39, when I use the second method to set the LSN at 3 turns out, I find that I get the equilvalent of 6.5 and 7 turns using method 1.
I'm just interested in what the std method for heli engines is, since I come from RC car background, and these engines have throttle stop screws, so method 3 is usually used. Thanks.