OFNA Racing Picco .21 Comp - Manual

Stop!! Carburetor screws are preset by factory.... Do not change until you read
break-in instructions
.
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 freer.
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 OFNA engine. So, you
must run the engine rich (COOL) for the first three tanks of fuel. We recommend using one gallon of 20% BLUE THUNDER
or BYRON'S 2000 as break-in fuel. Other break-in type fuels or added oil is NOT needed. DO NOT OVER REV THE
ENGINE WHEN FIRST STARTING, this could break the piston and over heat sleeve. Let engine run at a fast idle for one
tank to break-in connecting rod bearing before starting full break-in. Let engine cool down before continuing and never stop
engine with piston at top of the cylinder. This cool down period is for heat cycling the parts.
Break-in the engine in the car, by running the engine at a rich master needle setting (2 1/4 turns or more if needed). Run
the car from a slow to fast speed with short bursts of speed. You need to buildup a little heat (warm to the touch) in the
engine, but not too hot. In a rich setting (2 or more turns), the engine will run cold. In the leaner setting (2 or less turns),
the engine runs hotter. Do not heat up the engine too much at this time, let it cool down if too hot. After about one (1) tank,
turn the Master Needle Valve, clock wise, 1/16 of a turn leaner or clockwise. Keeping the fuel tank full, continue the
process until you slowly turn the Master Needle Valve, 1/16 of turn each time, too a leaner point and in which the engine
runs at high RPM and power, but still keep max temp. of 250 deg. F. At this point you must stop, too lean of a setting will
heat up engine and damage the piston. A normal operating temperature is around 220 to 270 Deg. Temperatures of 300
Deg. and above will damage engine and shorten life.
STARTING NEEDLE SETTINGS
Master Needle Valve - main control for fuel mixture. Set at 2 to 2 1/2 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!!
Barrel Needle (Low Speed) - 7mm Carburetor, factory setting is " Turn needle in until is stops, do not over tighten. Now,
turn out counter clockwise 10.5 to 11.5 turns. This needle is in the center of the carburetor barrel and provides throttle
response. It is not the idle adjustment. Turning screw "IN" is Lean and "Out" is Rich. Do not adjust this needle until the
Master Needle is set for power and best performance. This needle will only effect throttle response, so adjust needle until
throttle response is clean with little or no delay. Once set, do not continue to turn (lean) needle further. This is important
since continuing to turn needle will only increase engine temp, at lower RPM, which will throw off engine overall tuning.
Barrel Stop Screws - Used for adjusting Idle. Set for 1/16th inch gap to start new engines. You can open more for faster
idle.
USE LONG GLOW PLUG WITHOUT IDLE BAR,
(OFNA/PICCO 51007 PLUG) IS RECOMMENDED
OFNA/PICCO .21 COMP
ENGINE
#51215 .21 SG WITH BOOST
CHAMBER