Repairs Does my Lazer Z have an alternator or a magneto?

shodges7977

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I've had a weird issue this summer where my battery would drain between mowings (4-6 days) ... I would jump start it and it would run fine .... then it started shutting off mid-mow, so I replaced the battery and have had the exact same issue several other times. When it has shut off I would charge the battery back to full strength and it would then crank up fine. So obviously it's losing amperage while I'm mowing. I can't figure out why and wondered if I have an alternator or a magneto? And if anyone knows the answer to that question, any idea how I go about testing either?

I have a 5100 series Lazer-Z model LZ23KC604
 

bertsmobile1

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You have both
The magneto generates the ignition spark and is outside the flywheel.
The alternator generates the electricity to replenish the battery & run the clutch.
It is on the inside of the flywheel.

If the magneto is bad there is no spark, so the engine stops

If the alternator &/or rectifier is bad the battery runs down so the solenoid on the carb closes & the engine stops.

To give you meaningful instructions w need to know which brand of engine and what the engine numbers are.
 

shodges7977

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Thanks Berts!
Kohler Command SP 23
Model CH23
Spec No 24522252
Serial No 4703406401
 

shodges7977

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And just to reiterate, I can always get the mower running again by either jumping the battery or charging the battery. And there has been no rhyme or reason to when it wont crank or when it shuts off mid-mow.
 

bertsmobile1

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I can not look up the exact spec but can point you in the right direction.

I shall use this diagram from Jacks as a refference https://www.jackssmallengines.com/jacks-parts-lookup/manufacturer/kohler/oem-cross-reference/exmark-mfg/ch23-76569-exmark-mfg-23-hp-17-2-kw/ignition-electrical-5-24-372-ch18-750
Locate the regulator , part # 39 on the side of the blower housing.
There should be a flat strap, part # 37 bridging the engine ( ground ) to the outside of the regulator making the ground contact for it.
This strap regularly breaks so the rectifier is not grounded & can not recharge the battery.
When I repair them, I make some new wires with eye terminals to go between a blower housing screw & the rectifier ( one each side to a different screw ) .
Once you have located the rectifier measure the voltage from the purple wire to ground and to the battery negative , engine off & engine running full speed.
Also measure the same points for AC voltage. If you get an AC reading then the rectifier is toast & needs replacing.
Also measure the AC voltage between the two white or yellow wires to ground and between each other.
The ground readings should be the same and the reading between the two should be between 28 V & 36 V AC that will end up being 13 to 14 V DC by the time the mower sees it.
If these don't happen then the alternator is cactus
At this point stop, remove the blower housing and remove the flywheel, check that the magnets are all there & not fallen off.
Assuming the previous is not the case & the alternator is good, then measure the voltage Purple to battery negative and between the battery terminals, engine running full speed.
If these are different then the purple wire has broken somewhere so the volts are not getting back to the battery.

Post your results.

After that then clutch is the next culprit , but like learning to walk, one step at a time.
 

shodges7977

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Thanks guys, i'm going to finish my regular/weekly mowing season and then work on this issue. I'll report back at some point with results. Really appreciate the input.
 
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