Re: 2000 John 35 hp Shuts down after start up!!
To test power pack:
Check the power pack cranking output first as follows:
Set the peak reading voltmeter to read positive on the 500 volts scale.
Twist and pull the primary lead from the power pack off the ignition coil. Install the Stevens PL-88 load adapter connecting the red end of the adapter to the primary wire lead and the black end of the adapter to a good engine ground.
Connect the black DVOM lead to a good engine ground also, then connect the red meter lead to the red end of the test adapter (where it connects to the primary wire).
Crank the engine and observe meter reading, it should be 100 volts or higher. Record the results, remove the test adapter and reconnect the wiring. Repeat the cranking output test for each of the remaining ignition coil outputs from the power pack.
Interpret the meter readings as follows:
If the meter reads at or higher than specification, but the ignition is not performing properly for the spark test, check the Ignition Coil as detailed in this section.
If the primary lead has no output, check the Charge Coil as detailed in this section (if not already tested earlier). If the charge coil is good, then visually inspect the optical sensor for dirt, debris or damage. If no visible sensor damage is found, the only method for testing whether the problem is the sensor, encoder or power pack is to substitute a known good component (one at a time) until the system operates properly.
To check the power pack under load, at engine speeds where intermittent problems are noted, proceed as follows:
Connect a source of cooling water to the engine, as detailed under Flushing the Cooling System in the Engine Maintenance section.
If the engine is to be run at speeds over 2000 rpm, it must be mounted in a test tank using a suitable test wheel or placed in the water to prevent possible overspeed and damage which could occur if the engine was run on a flushing device.
Install a terminal extender to the primary terminal of the ignition coil whose power pack signal is being tested.
Set the peak-reading DVOM to read positive 500 volts scale, then connect the black meter lead to a good engine ground and the red meter lead to the metal portion of the terminal extender.
Double-check to make sure the test leads are routed so they will not be damaged by rotating parts, then start and run the engine. If the engine is to be run above high-idle, allow it to warm before advancing the throttle.
With the engine running, power pack output should be at least 240 volts and should remain steady at a constant engine speed. If a problem has been noted at a particular engine speed, attempt to duplicate the symptom while observing the meter. Output must not dip below the specified voltage output for engine running conditions. Repeat the running output test on the power pack signals for the remaining engine coils.
If the meter reads less than specified, test the Charge Coil (if not done already), as detailed in this section. If the charge coil is good, then visually inspect the optical sensor for dirt, debris or damage. If no visible sensor damage is found, the only method for testing whether the problem is the sensor, encoder or power pack is to substitute a known good component (one at a time) until the system operates properly.
Reconnect all wiring as removed for testing.
Hope this helps.
