OFNA Racing 21 P4, Black T8 User Manual

FORCE 21 P4

FORCE 21 P4 PULL START

FORCE BLACK T8

ENGINES

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.

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 0R 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 270 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 1 1/2 to 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 the brass 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.

FOR THREE NEEDLE CARBURETORS, DO NOT ADJUST MID RANGE NEEDLE, PRESET BY FACTORY

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 IS RECOMMENDED

OFNA RACING , 22692 GRANITE WAY, STE. B, LAGUNA HILLS, CA 92653. TEL:[phone]

FORCE 21 P4

FORCE 21 P4 PULL START

FORCE BLACK T8

FORCE .21 AND SUPER FORCE .21

52010 FM-2101 HEAD, TALL BLUE 38.50
52011 FM-2101-1 HEAD, BUTTOM REPLACEMENT 10.95
52030 FM-2103 HEAD, SHIM 1.75
52040 FM-2104/5-4P CYLINDER SLEEVE AND PISTON, 4 PORT 64.95
52041 FM-2104/5-6P CYLINDER SLEEVE AND PISTON, 6 PORT 75.95
52060 FM-2106 CONNECTING ROD (ALUM. 7075S) 14.95
52070 FM-2107 CRANKCASE, FORCE P4 29.95
52071 FM-2107A CRANKCASE, SUPER FORCE P6 29.95
52080 FM-2108 CRANKSHAFT, P4 12mm 29.95
52081 FM-2108PS CRANKSHAFT PULL START, P4 12mm 29.95
52082 FM-2108SG CRANKSHAFT SG, P4 12mm 38.95
52090 FM-2109 REAR BACK COVER 6.25
52091 RS-12/17 REAR BACK PLATE UNIT, PULL START 24.95
52098 RS-18/19 SPRING AND PIN, PULL START 3.95
52099 RS-1/11 PULL START UNIT W/ ROPE 24.95
52100 FM-2110 CARBURETOR SET PIN 3.25
52110 FM-2111 SLIT METAL CONE 2.95
52120 FM-2112 DRIVE HUB 3.25
52130 FM-2113 CARBURETOR BODY, P4 / P6 11.75
52131 FM-21131(7mm) CARBURETOR COMPLETE, 7mm 61.95
52140 FM-2114 THROTTLE BARREL 6.75
52150 FM-2115 THROTTLE NEEDLE 3.75
52160 FM-2116 SPRING, THROTTLE NEEDLE 1.25
52170 FM-2117 BOOT, THROTTLE 2.50
52180 FM-2118 CAP, THROTTLE NEEDLE(OLD) 2.25
52181 FM-2118ST BALL END, THROTTLE NEEDLE 5.95
52190 FM-2119/20 BARREL STOP BASE AND NUT 2.25
52219 FM-2121 BARREL STOP SCREW 2.25
52220 FM-2122 LOW END NEEDLE 4.75
52230 FM-2123 WASHER, ALUMINUM, 1 PC 0.95
52240 FM-2124 FUEL SUPPLY NIPPLE 2.50
52250 FM-2125 MAIN NEEDLE SEAT 4.25
52260 FM-2126 MAIN NEEDLE 3.75
52270 FM-2127 CRANKSHAFT, P6 13mm, THREADED 31.95
52271 FM-2127S CRANKSHAFT, SG , P6 13mm, SG 64.95
52900 FMB-1 BEARING, OUTSIDE, 607Z 5.95
52910 FMB-2 BEARING INSIDE, 6901 8.50
52920 FMB-3 BEARING INSIDE, 13mm 18.95
52930 FML-1 SEAL, REAR COVER 1.75
52940 FML-2 SEAL, CARBURETOR 1.25
52950 FML-3 SEAL, LOW END NEEDLE 0.95
52960 FML-4 SEAL, MAIN NEEDLE 0.95
52970 FMP-1 PIN, PISTON 2.25
52980 FMS-1/2 SCREW SET, 8 PCS 2.50
52990 FMW-1 CLIPS, “G”, 2 PCS. 1.25

DELTA FORCE .21 P8 AND T8

52012 FM-2101-1T DELTA HEAD, BUTTON, TURBO PLUG 19.95
52013 FM-2101-1S DELTA HEAD, BUTTON, STD PLUG 19.95
52015 HEAD, T8 FORCE, BLACK 43.95
52043 FM-2104/5T-P8 BLACK DELTA CYLINDER SLEEVE AND PISTON, P8 PORT 85.95
52044 CP-2104/5ST-T8 BLACK DELTA CYLINDER SLEEVE AND PISTON, T8 PORT 85.95
52062 FM-2106S DELTA CONNECTING ROD (ALUM. 7075S), P8 19.95
52063 FM-2106ST DELTA CONNECTING ROD (ALUM. 7075S), T8 19.95
52072 CRANKCASE, SILVER P8 36.95
52073 CRANKCASE, BLACK T8 39.95
52101 FM-2110 CARBURETOR SET PIN (P8) 4.95
52135 FM-2113ST-1 DELTA, CARB, 3 NEEDLE (NEW) T8 65.95
52272 FM-2127T CRANKSHAFT P8,SG, TURBO 67.95
52273 CS-2198T CRANKSHAFT T8, SG, TURBO 75.95

ENGINES

OFNA RACING , 22692 GRANITE WAY, STE. B, LAGUNA HILLS, CA 92653. TEL:[phone]