100 Tractor Tune Up Info
Engine Model And Type
C-123 Gas
C-123 Dist.
C-123 Gas Fire Crater Pistons*
C-123 Flat Top Pistons*
Compression Pressure (at cranking speed)(psi)
140
95
125
101
High Idle (no load) Engine RPM / PTO RPM
1575 / 609
1575 / 609
1575 / 609
1575 / 609
Low Idle (no load) Engine RPM / PTO RPM
425 / 164
425 / 164
425 / 164
425 / 164
Rated Load Speed Engine RPM / PTO RPM
1400 / 541
1400 / 541
1400 / 541
1400 / 541
Horsepower (at load speed) PTO Shaft
20.8
17.1
23.1
19.4
Approximate Fuel Rate (at load speed) gals/hour
1.91-2.02
1.75-1.85
2.30-2.40
2.14-2.23
Firing Order
1-3-4-2
1-3-4-2
1-3-4-2
1-3-4-2
Valve Lash (hot)(inch)
Intake
.014
.014
.014
.014
Exhaust
.014
.014
.014
.014
Spark Plug Gap (inch)
.023
.023
.023
.023
Distributor
Symbol
J
J
J AB
J
Breaker Point Opening (inch)
.020
.020
.020
.020
Part Number
357935R91
357935R91
372712R91
357935R91
Governor Spring Package
358108R91
358108R91
372785R91
358108R91
Ignition Timing (spark advance BTDC unless otherwise specified) (degrees)
At 400 RPM (+ or - 2 Degrees
0
0
1
0
At high Idle Speed
30
30
22
30
Carburetor Liquid level (inches)
I.H.
-
-
-
-
Zenith
1/2
1/2
1/2
1/2
Carter
17/64
17/64
17/64
17/64
Marvel-Schebler
-
-
-
-
Torque Wrench Settings (foot pounds)
Cylinder Head
80
80
80
80
Manifold
20
20
20
20
Increased Bore