OFNA Racing Hyper .21 - Manual (Page 2)

MASTER NEEDLE
FACTORY SETTING: 3.5 to 4 TURNS OUT FROM CLOSE
FUNCTION: SET MAX SPEED AND POWER.
MID RANGE NEEDLE
DO NOT TURN!
FACTORY SETTING: HEAD IS
FLUSH TO CASE
BARREL STOP OR
IDLE SCREW
FACTORY SETTING:
1/16 AIR GAP
LOW END NEEDLE
FACTORY SETTING:
HEAD IS FLUSH WITH BALL COLLAR
SET: 1/2 TURNS OUT
FUNCTION: ADJUSTS THROTTLE
RESPONSE.
NEEDLE FUNCTION
Master Needle Valve - main control for fuel mixture. Set at 3.5 to 4 turns out from closed OR 1/2 turns in from top flush.
Adjust this needle for maximum RPM and power without being too lean or too hot. Make sure you start at bottom of needle
seat!!
Side Black Carburetor Needle (Low End) - This needle is in the center side of the carburetor barrel and provide throttle
response. It is not the idle adjustment. Set 1/2 turns out from FLUSH with the black ball sleeve. Turning IN is Lean
and OUT is Rich. Do not adjust this needle until the Master Needle is set for power and top speed. This will only effect
throttle response.
Mid Range Needle (brass) - DO NOT ADJUST MID RANGE NEEDLE, FACTORY SETTING IS FLUSH TO CASE.
Barrel Stop Screws - Used for adjusting Idle. Set for 1/16th inch gap to start new engines. You can open more for faster
idle. Set idle below clutch engagement.
USE LONG GLOW PLUG WITHOUT IDLE BAR,
OFNA #51010 HOT OR #51011 MEDIUM.
SHOWN AT
"FLUSH
SETTING"
HYPER .21 ENGINE