Here's a link to the manual:
http://media.hobbypeople.net/manual/146027.pdf
From the manual:
Low Speed Needle Valve
The low speed needle valve meters the air/fuel mixture at idle and
during transition from idle to full throttle. Turn the low speed needle
clockwise to lean the mixture. Turn it counter-clockwise to richen
the mixture. The low speed needle valve is preset from the factory,
but minor adjustments may need to be made to suit your application:
fuel used, glow plug and environment all contribute to the setting.
To reset the low speed needle valve to the factory setting, follow
these simple steps:
q 1) Open the carburetor barrel completely.
q 2) While holding the barrel open with your finger, use a flat blade
screwdriver to turn the idle mixture needle clockwise until it stops.
From this point, turn the needle counter-clockwise 8 turns. This is
the factory setting.
High Speed Needle Valve
The high speed needle valve is used to meter the air/fuel mixture at
full throttle. Using a flat blade screwdriver, turn the needle clockwise
to lean the mixture or turn the needle counter-clockwise to richen
the mixture. When you start the engine for the very first time, the
needle valve should be turned in completely, then backed out 3 turns.
When you start the engine after that, leave the needle valve in the
same position it was in when you shut down the engine.
