75611A86 Mercruiser GASKET SET, ENGINE OVERHAUL

Safety
Do not operate or work on this product unless you have read and understood the instruction and warnings in the relevant Operation and Maintenance Manuals and relevant service literature. Failure to follow the instructions or heed the warnings could result in injury or death. Proper care is your responsibility.
Required Tools
Table 1
Required Tools
Item Qty Part Number Part Name
T1 1 393-0673 EMISSIONS ANALYZER TOOL GP
T2 1 391-8170 EMISSIONS ANALYZER TOOL GP (Bluetooth Module) Procedure
Set the Natural Gas Fuel Supply Pressure
The regulator should be sized so that the supply pressure to the tecjet fuel valve is between 0.5 psig minimum at rated load and 5 psig maximum at idle. The regulator must be able to provide constant pressure to the tecjet from cranking speed to full load.Determining the Ignition Timing
The timing parameters allow the customer to program the ignition timing of the engine to meet the needs for specific applications and installations.Note: Timing will be provided within the Gas Engine Rating Pro (GERP) program.First Desired Timing
The "First Desired Timing" is determined with the methane number of the primary fuel that is being used. Obtain the timing information for the specific fuel and site conditions from the local Caterpillar dealer. The timing can also be obtained using the Caterpillar® Gas Engine Rating Pro (GERP) software program.Note: If the fuel composition at a given site changes greater than three methane points, the timing will need to be reset. Contact the local dealer or use GERP if such a change occurs.A free copy of GERP can be obtained by going to the following link and searching GERP in the search field. More information regarding the GERP program can also be obtained from the following website.https://catoilandgas.cat.com
GERP can provide the maximum rating capability for conditions at a given site. Use the following procedure to use GERP.
Select "Electric Power" under the "Application" drop-down box.
Select the desired engine.Setting the Ignition Timing
Use the following procedure to set the timing value found in the "Determining Ignition Timing" section using the engine display panel.
Select "Main Menu".
Select "Configure".
Select "All Set Points".
Select "Engine Configuration Parameters".
Select "Timing Control".
Select "Desired Engine Timing".
Select and change the "Desired Engine Timing".Initial Set-Up Procedure
Ensure that all these factors are in proper working condition prior to the initial start-up: engine installation, driven equipment, all the related hardware and electrical connections. Failure to perform the commissioning procedure could result in unsatisfactory operation.Perform the following procedure for the initial start-up and for start-up after major maintenance and/or after repair.Note: Use Cat® Electronic Technician (Cat ET) Service Tool, version 2019C or later.
Current fuel analysisObtain a fuel analysis for natural gas fuel quality supplied to the engine. The following parameters are required to input into Cat ET:
Gas Lower Heating Value (LHV)
Gas Specific Gravity
Fuel specific Heat Ratio
Illustration 1 g06531878
Engine load factor equation
(1) Generator load (ekW)
(2) Generator efficiency
(3) Auxiliary driven load (kW)
(4) Engine load factor
(5) Engine rated power (bkW)
Update engine load factor parameters in Cat ET.Note: The following parameters impact the engine software load factor calculation, which uses the equation shown above.The accuracy of these parameters will impact the performance and emissions of the engine.
Engine driven accessory load.The total accessory load at 1800 rpm must be input into Cat ET. This accessory load includes a package mounted-radiator and alternator (if applicable). Use the following guidance for load:Package Mounted Radiator: 30 kW (40 hp)Alternator: 3 kW (4 hp)If the generator set is not using a package-mounted radiator or alternator, this value must be set to 0 kW (0 hp).
Generator efficiency configuration.Input expected generator efficiency into ET. This efficiency is based on power factor and maximum electric load that the generator set is able to achieve at operating site.
Check EmissionsNote: Desired NOx level has been disabled in Cat ET. For emissions compliance, the desired NOx level has been hard-coded to 250 ppm in the engine softwareBy using ET, monitor the NOx PPM. The NOx PPM screen will display the value shown on the analyzer ( 10 PPM) for a 5 minute period. If not, proceed to step 4.
Calibrate the NOx sensor.Note: Desired NOx level has been disabled in Cat ET. For emissions compliance, the desired NOx level has been hard-coded to 250 ppm in the engine softwareThe NOx sensor must be calibrated at initial engine setup, with changes in fuel quality on site, and whenever the sensor is replaced. A calibration procedure is available in Cat ET. This procedure adjusts the slope of the sensor to account for this drift.During the calibration, the concentration of NOx that is reported by Cat ET is compared to the actual concentration that is reported by an emissions analyzer.Note: Make small changes to the slope value during the calibration procedure. If large changes are made to the slope value, the engine operation may become unstable. Allow engine to stabilize after each adjustment is made.Before a calibration of the NOx sensor is performed, obtain a recent gas analysis of the fuel to confirm the settings of the engine fuel quality and specific gravity. If necessary, update the configurable parameters in Cat ET.Calibration must be done during controlled engine operating conditions. The engine must be running and the operating conditions of the engine must be stabilized. Ensure that the requirements that are displayed on Cat ET are satisfied prior to initiating the calibration. If these conditions are not maintained during the entire calibration procedure, the calibration will be aborted.
Start the engine, allow the engine to warm to normal operating temperature.
Connect a 391-8170 EMISSIONS ANALYZER TOOL GP (Bluetooth Module) or a 393-0673 EMISSIONS ANALYZER TOOL GP to the engine exhaust system.
Allow the NOx readings from the analyzer to stabilize.
Connect Cat ET to the service tool connector. Establish communications with the ECM.
Access the "Service/Calibrations/Engine Exhaust NOx Level Sensor Calibration" screen of Cat ET. Use Cat ET to start the calibration.
Follow the prompts to guide you through the calibration procedure. Be sure to allow the engine to stabilize before each measurement is taken.
Compare the value of the NOx that is reported from