STEM ASSEM. (straight) 7S9370 - Caterpillar

1. New 2301A Governor Control Limits Rack Travel At Start-Up And Controls Acceleration Rate
Reference: Special Instruction, SEHS9188, "Installation of 7E5253 Governor Control Assembly". Service Manual, SENR3585, "2301A Electric Governor."The 2301A Governor Control replaces the former 2301 Governor Control and aids in reducing rough combustion after start-up. It provides a means to limit fuel delivery during start-up and acceleration of the engine. A 7E5253 Governor Control (Woodward 2301A) can be installed in place of the former 4W5392 Governor Control (Woodward 2301) by following the directions given in the Special Instruction. The START FUEL LIMIT control should be set to allow the minimum amount of fuel possible to start the engine. The RAMP TIME control should be set to the maximum time allowable to the application in which the engine must operate. (For example, if the engine is in a standby application operation with a 10 second load capability requirement, the RAMP TIME control should be set for as long a time as possible to just make the 10 second time requirement.) Instructions for adjusting the 2301A Governor are in the Service Manual.
2. Jacket Water Heaters Keep Coolant Warm In Low Ambient Conditions
Reference: Special Instruction, SEHS9340, "Jacket Water Heater Installation Procedure".Keeping the coolant warm when the ambient temperature is below 10°C (50°F) aids in preventing rough combustion after start-up. The 7E6249 (120 Volts) or 7E6248 (240/480 Volts) Jacket Water Heater Group can be installed. The new jacket water heaters can be installed on either side or both sides of the engine. To install a jacket water heater, a mounting group and jacket water heater group must be ordered. The chart identifies the right and left hand mounting groups for the appropriate engine.
It is recommended that a jacket water heater group be installed on each side of the engine to get even heating of the engine. 3. New Water Regulator Prevents Leakage
Reference: Service Magazine; June 25, 1990; Page 14; "New Water Regulator Prevents Leakage". This prevents coolant, warmed by jacket water heaters, from leaking past the regulator and going to the radiator. The new 7E7933 Water Regulator is a direct replacement for the former 4W4794 Temperature Regulator.
4. New Water Regulator Housing Eliminates Drain Hole
Elimination of the drain hole that was used to drain coolant from the top housing to the bottom housing prevents coolant, warmed by the jacket water heaters, from going to the radiator. The 9Y4090, 8N9623 and 8N9624 Lower Regulator Housings were changed to eliminate a drain hole.
The 9Y9121 Upper Regulator Housing can be plugged for engines produced prior to the serial numbers listed in the chart. To plug the hole, remove the top regulator housing and tap the 10.5 mm (.41") to accept a 7F9504 Plug (1/4" Standard pipe thread. When installing the plug in the tapped hole, make sure the top of the plug is flush with or slightly below the surface of the housing. See illustration for location of hole.
After the hole has been plugged, the upper housing cannot be completely drained in the