Originally Posted by Roelof

You need to set the EPA a bit larger, not to the ventury but take out the vantury and be sure the barrel goes a little bit beyond the opening. That is needed to be sure the carb stays maximized open that flex in the chassis while running at full speed can not cause a small jitter on the full throttle.
The same with idle, you need to have some small space when moving the throttle before it will move the carburator to prevent a jitter on idle with vibrations in the chassis.

The LSN is basically the acceleration screw. If the top speed has a nice constant speed/sound then the LSN will determ the speed how fast it will reach the top speed. And there is a limit when you notice it will hold in. Just find a good setting and do not go too lean unless you want to win races.

It is true that the glowplug need to or just can be chosen with the outside temperature but air pressure and humidity also plays a role so it is no standard must. It is all about ignition timing. Because these engines work on a self combustion the ignition is determed by all kind of factors (weather, nitro, plug number and headplay), the glowplug is one of them. With some shifting of the ignition timing you can controll the behavour of the engine, more rpm when it is set to a later ignition (colder plug) and more bottom torque with a sooner ignition (hotter plug)