RE: O.S 1.60FX Owners. Post your tach readings
Your profile says you are running an OS .46 in a Aeroworks Edge. I don't believe it's necessary to do this to the small engines. From teh OS 120 manual
"The same applies if the silencer type is
changed. A different silencer may alter the
exhaust pressure applied to the fuel feed and
call for a revised Needle-Valve setting."