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The Magnetic pickup or more properly known as TRANSDUCER, MOTIONAL.
On the MEP-802A, it is located on the right side of the generator set. It’s mounted on the flywheel bell housing. It is listed in TM9-6115-641-24P, figure 20, item 13. As far as I can remember, it is located on the right side, of all TQG’s.
It “counts” the number of flywheel teeth passing by per second, (RPM) and “tells” the generator set how fast the engine/main alternator is rotating. It also allows you to among other things, to turn the S-1 Start Switch on, while the engine is running. Why is this important? Well, to give the main alternator its exciter voltage, (light it off) so the main alternator will start producing voltage, the engine needs to reach a minimum speed. When the Mag Pickup senses that the speed is high enough, and you have the S-1 in the start position, presto! It excites the main alternator and everyone is happy. Sometimes people let the S-1 switch snap back to the RUN position too soon. The main alternator doesn’t light off, and no voltage is produced. Generator set runs, but no output. Solution? Turn the S-1 to the start position for a few seconds, and presto! Voltage. Everyone’s happy.
Should you ever, on ANY TQG generator set, (MEP-802 to MEP-806) hold the S-1 in the start position and the starter motor grinds on the flywheel, STOP THE MUSIC. Turn off the set. Look at the two wires coming out of the Mag Pickup. Are they hooked up, or not broken? Then unhook the two wires. Get a voltmeter, and turn it to AC voltage, (yes, AC) and poke the voltmeter leads into the terminals on the Mag Pickup. Ask your trusted buddy, wife or a passing hobo to turn over the engine using the S-10, Dead Crank Switch. You want the engine to turn over, but not start. Your voltmeter should read while the engine spins, 3 volts AC. It’s good from 2.5 to 3 volts AC, BUT 3 volts is what the perfectionist wants. If you get no volts, it’s time to start cussing.
The correct adjustment procedure is in the TM, but here is the short version. Screw out the Mag Pickup from the bell housing and look at it. Is the end ground off? That’s what it normally looks like with a no volt reading. Start looking for a new one. If it’s not ground off, clean it. Tiny metal chips, from the grinding starter, can cover the end of the magnet on the end of the Mag Pickup. Giving bad signals to the set. Once it’s clean, screw it into the bell housing until it bottoms out. Turn it counterclockwise ¾ of a turn. Hand tighten the counter lock nut on the mag pickup. Ask the passing hobo to once again turn the generator over with the S-10 and read the voltmeter. Stop the set. Is the reading less than 2.5 volts? Turn the Mag pickup clockwise a tad. But only a tad. Or you will be looking for a new Mag Pickup, after you grind the end off. Repeat as often as necessary. When you have it at 3 volts, put a few drops of Loctite on the counter locking nut and tighten it down WITHOUT moving the Mag Pickup. The Mag Pickup is very robust. In all the years I have worked on generators, I have only seen 1 or 2 bad ones. Mostly its broken/unhooked wires or the end ground off. About 99% had the end ground off. The generators vibrate, so use Loctite everyplace.
On the MEP-802A, it is located on the right side of the generator set. It’s mounted on the flywheel bell housing. It is listed in TM9-6115-641-24P, figure 20, item 13. As far as I can remember, it is located on the right side, of all TQG’s.
It “counts” the number of flywheel teeth passing by per second, (RPM) and “tells” the generator set how fast the engine/main alternator is rotating. It also allows you to among other things, to turn the S-1 Start Switch on, while the engine is running. Why is this important? Well, to give the main alternator its exciter voltage, (light it off) so the main alternator will start producing voltage, the engine needs to reach a minimum speed. When the Mag Pickup senses that the speed is high enough, and you have the S-1 in the start position, presto! It excites the main alternator and everyone is happy. Sometimes people let the S-1 switch snap back to the RUN position too soon. The main alternator doesn’t light off, and no voltage is produced. Generator set runs, but no output. Solution? Turn the S-1 to the start position for a few seconds, and presto! Voltage. Everyone’s happy.
Should you ever, on ANY TQG generator set, (MEP-802 to MEP-806) hold the S-1 in the start position and the starter motor grinds on the flywheel, STOP THE MUSIC. Turn off the set. Look at the two wires coming out of the Mag Pickup. Are they hooked up, or not broken? Then unhook the two wires. Get a voltmeter, and turn it to AC voltage, (yes, AC) and poke the voltmeter leads into the terminals on the Mag Pickup. Ask your trusted buddy, wife or a passing hobo to turn over the engine using the S-10, Dead Crank Switch. You want the engine to turn over, but not start. Your voltmeter should read while the engine spins, 3 volts AC. It’s good from 2.5 to 3 volts AC, BUT 3 volts is what the perfectionist wants. If you get no volts, it’s time to start cussing.
The correct adjustment procedure is in the TM, but here is the short version. Screw out the Mag Pickup from the bell housing and look at it. Is the end ground off? That’s what it normally looks like with a no volt reading. Start looking for a new one. If it’s not ground off, clean it. Tiny metal chips, from the grinding starter, can cover the end of the magnet on the end of the Mag Pickup. Giving bad signals to the set. Once it’s clean, screw it into the bell housing until it bottoms out. Turn it counterclockwise ¾ of a turn. Hand tighten the counter lock nut on the mag pickup. Ask the passing hobo to once again turn the generator over with the S-10 and read the voltmeter. Stop the set. Is the reading less than 2.5 volts? Turn the Mag pickup clockwise a tad. But only a tad. Or you will be looking for a new Mag Pickup, after you grind the end off. Repeat as often as necessary. When you have it at 3 volts, put a few drops of Loctite on the counter locking nut and tighten it down WITHOUT moving the Mag Pickup. The Mag Pickup is very robust. In all the years I have worked on generators, I have only seen 1 or 2 bad ones. Mostly its broken/unhooked wires or the end ground off. About 99% had the end ground off. The generators vibrate, so use Loctite everyplace.