Super C 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)
125
95
125
101
High Idle (no load) Engine RPM / PTO RPM
1815 / 593
1815 / 593
1815 / 593
1815 / 593
Low Idle (no load) Engine RPM / PTO RPM
425 / 139
425 / 139
425 / 139
425 / 139
Rated Load Speed Engine RPM / PTO RPM
1650 / 539
1650 / 539
1650 / 539
1650 / 539
Horsepower (at load speed) PTO Shaft
23.7
18.9
25.6
21.0
Approximate Fuel Rate (at load speed) gals/hour
2.21-2.34
1.98-2.13
2.40-2.50
2.17-2.29
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
* Below Serial NumberFCM 150589 use Symbol "E", Distributor Number 354900R91 and Governor Spring Package 358108R91.
+ Increased Bore