OFNA Racing Hyper 10sc Nitro RTR - Manual (Page 36)

OFNA RACING , 7 VANDERBILT, IRVINE, CA. 92618 • TEL:(949)586-2910
Thank you for purchasing a OFNA engine. We appreciate your choice and know you will enjoy running it. Please
note that the OFNA information in engine box is subject to change without notice.
NEW ENGINE BREAK-IN
Your OFNA engine is extremely tight when the piston is at the top of the stroke and turning the crankshaft by hand.
This is normal for a new ABC type engine. The piston and sleeve are matched for fit and the top of the sleeve is
tapered for a tight fit. As you run your engine, this tightness Should diminish. There is no cause for alarm, because
as the engine warms up, the brass sleeve will expand faster than the aluminum piston and the engine will turn free.
As with any new engine, there are many high spots and tight fits in the matching process. High spots create hot
spots that must be broke-in. Therefore, the break-in process is very important to provide good service by the
engine. So, you must run the engine rich (COOL) for the first two tanks of fuel. We recommend using 20% O’Donnell
0R BYRON’S 2000 as break-in fuel. Other break-in type fuels or added oil is NOT needed. DO NOT OVER REV. THE
THE ENGINE WHEN FIRST STARTING, this could break the rod, piston and over heat the sleeve. Let the engine run at
low RPM for one tank to break-in connecting rod bearing before starting full break-in.
Break-in the engine in the car, by running the engine at a rich setting. Factory high end or master needle is 4 turn
Little heat in the engine, but not too hot. In a rich setting, the engine will run cool. In the leaner setting the engine run
Hot running hot is NOT good yet. Do not heat up the engine too much at this time. After about two (2) tank,
turn the Master Needle Valve, clock wise, 1/8 of a turn leaner or clockwise. Keeping the fuel tank full, continue the
process until you slowly turn the Master Needle Valve, 1/8 of turn each time, to a leaner point and in which the
engine runs at high RPM and power and the master needle should be at 3-3.5 turn out from close, but still keeping
If you go over 250 degrees it is too lean of a setting and will over heat the engine and damage the piston.
Normal operating temperature is around 220 to 250 Deg. Temperatures of 260 Deg. and above will damage
NEEDLE SETTINGS After break-in:
Master Needle Valve - (High End) Set at 3 to 31/2 turns from closed. 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 Carb. Needle (Low Speed) - This needle is in the center side of the carburetor where the blue boot is, provide
Throttle response. It is not the idle adjustment. Set NEEDLE flush with the ball end. Turning in is Lean and Out is Rich.
This needle until the Master Needle is set for power and top speed. This will only effect throttle response.
Barrel Stop Screws - Used for adjusting Idle: Set for 1/16th inch gap to start new engines. You can open more for
faster idle.
OFNA/PICCO GLOW PLUG IS RECOMMENDED
Do not adjust
HYPER 18 ENGINE
PART # 53121
Out from all the way close. Run the car from a slow to fast speed with short bursts of speed. You need to build
The MAX TEMP UNDER 250 DEGREES F.
Engine an shorten the life of the motor.
51010 - B4 STANDARD HOT
51011 - B5 STANDARD MEDIUM
51012 - B6 STANDARD COLD
51013 - T4 TURBO HOT
51014 - T5 TURBO MED
51015 - T6 TURBO COLD
Mid Range needle - The brass needle on the side of the carb. DO NOT TOUCH.