OFNA Racing 32 User Manual
FORCE 32 PULL START
Thank you for purchasing a OFNA engine. We appreciate your choice and know you will enjoy running it. Please
note that theForce information in engine box is subject to change with not notice.
Carburetor Low end and barrel stop screws are pre-set by factory.... Do not change until break-in is done.
ENGINES
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% 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 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. Run the car from a slow to fast speed with
short bursts of speed. You need to buildup a little heat in the engine, but not too hot. In a rich setting, the engine
will run cold. In the leaner setting the engine run hot, this is not good yet. Do not heat up the engine too much at
this time. After about one (1) 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,
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 250 Deg. Temperatures of 300 Deg. and above will damage engine and shorten life.
NEEDLE SETTINGS
Master Needle Valve - main control for fuel mixture. 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 Carburetor Needle (Low Speed) - This needle is in the center side of the carburetor and provide throttle
response. It is not the idle adjustment. Set FLUSH with ball end. 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.
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 OR 51008 IS RECOMMENDED
OFNA RACING , 7 VANDERBILT, IRVINE, CA. 92618 • TEL:(949)586-2910
FORCE 32 PULLSTART ENGINES
OFNA DESCRIPTIONS RETAIL OFNA DESCRIPTIONS RETAIL
10330 COLLET, FLYWHEEL INSERT.12/.21-.32 2.95 52286 CONNECTING ROD .28-.32 22.95
52090 REAR BACK COVER, FORCE .28-.32 6.95 52291 BEARING, REAR .32 30.95
52091 PULL ST BACKPLT, .21-.32 24.95 52293 HEAD GRAY .32 33.95
52292 HEAD BUTTON .32 32.95 52294 CRANKCASE .32 42.95
52093 ONE-WAY BEARING, PULL START 19.95 52295 PISTON / SLEEVE .32 106.95
52098 PIN & SPRING- .26-.32 3.95 52296 PISTON/SLEEVE/CON/ROD 124.95
52099 PULL START, ASSEMBLY 21-32 ENG 24.95 52297 CRANKSHAFT SG .32 59.95
52100 CARB SET PIN (FORCE) .28-.32 3.95 52298 HEAD SHIM 0.2mm .32 ENG 1.95
52140 THROTTLE BARREL 8.95 52299 WRIST PIN .32 2.95
52181 BALL CAP, THROTTLE 5.95 52300 THROTTLE BOOT .32 2.95
52250 MAIN NEEDLE SEAT 4.95 52900 BEARING, FRONT .21-.32 5.95
52260 MAIN NEEDLE 3.95 52930 SEAL, REAR COVER 1.95
52274 WASHER, MAIN NEEDLE SEAT UPPER 1.95 52930 SEAL, REAR COVER 1.95
52275 NIPPLE FUEL SUPPLY BRASS 7.95 52940 SEAL, CARB. upper/lower 1.95
52276 WASHER, MAIN NEEDLE SEAT LOWER 1.95 52960 SEAL, MAIN NEEDLE 0.95
52277 CARB. BODY, .28 & 32 16.95 52960 SEAL, MAIN NEEDLE 0.95
52278 BARREL STOP SCREW .28-.32 2.95 52980 SCREW SET, 8 PCS 2.50
52279 LOW END NEEDLE .28-.32 4.95 52990 G-CLIPS, 2 PCS. 1.95
52282 CARB. COMPLETE .28 & .32 59.95
52208 FORCE .32 SG 6P w/PULLSTART PART LIST
PART # 52208 w/PULLSTART
TECHNICAL DATA
•Cubic Capacity.............5.22cc •Rpm............................39000
•Stroke................................17.5 •Hp...................................2.9
•Bore............................19.5mm •Weight..........................350gr
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