[hawkman]

Hi there,

There are two settings, usually, for the carb....the main needle is the larger one...which it sounds like you already know. The other setting is the 'low end' or the idle needle...this is sometimes located within the throttle barrel...look for a small screw...but dont adjust it yet.

Ok...run the engine and get it to a nice idle..now pinch the fuel line about 3 to 4 cms back from the carb...and listen to the engine idle...if the revs increase straight away you are too lean....if the engine idles for 2 to 3 seconds before rising in revs and then stopping then you are ok. If it goes for 3 to 4 seconds and longer its too rich.

Too rich? screw the idle or low end needle IN...use very small adjustments...a quarter turn will make a difference.

Too lean? then screw the low end OUT a touch.

Repeat the pinch test and adjust as needed.

The low end or idle will affect the engine revs from idle to about mid range...the main needle will have an affect of course but 2 turns out from closed sounds about right for this.

Too lean an engine usually means the engine can be very revvy but will get hot.

Fly about for a while and then land...be careful of the rotors of course..but go to idle and use a finger to touch the backplate of the engine...if its warm thats ok...but if its hot then you could be too lean or the pitch range/throttle range needs revising...too much pitch and low revs can overload an engine...the mixture going through the crankcase helps to cool the engine and its bearings.

The engine sounds powerful enough, I have one in my loft with an old Concept which will never fly again. Just got myself an OS 37 for my Sceadu.

Rob