New "40 Amp" Alternator

Joined
Mar 13, 2012
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soCal
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'97 ST1100
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687
I finally got my '98 ST1100 started after doing a bunch of work on it, including installing a new Chinese alternator.

So far, so good. Some feedback for Martin's ( ST1100Y ) concern about the idle charging voltage.

With my low beams and two smaller LED spots on, idling at 1,000 RPM the charging voltage is 14.1 volt and two green LED's are on on my Kuryakyn LED voltmeter.

Idling with all lights off ( I added a switch so I can turn off the low beams ) , the charging voltage is 14.4 volts and two green LED's are on on my Kuryakyn LED voltmeter.

Idling with the high beams on and two smaller LED spots and two really big LED spots on, the charging voltage is 13.7 volts and one green LED's is on on my Kuryakyn LED voltmeter performed.

This is about the same as my original OEM alternator.
thanks for the info Jim, very helpful, although I hope I never need it.

did you have an alternator failure on your '98??
 
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Jim Van
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Doug : No failure, just concerned one might occur in the near future. I'm planning on doing a 2,650 mile IBA Great Lakes 100 ride in July.

And I'm not a member of the " If it ain't broke, then don't fix it " club. I'll hold on to the old alternator for a few years. Then I'll put it on EBay or sell it to a ST Forum member that wants to do an alternator upgrade. Planning on getting a used 2018 Gold Wing at that point, if I'm still respirating and riding.
 
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kiltman

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Thanks for the update Jim. Nice to know that it is performing as well a the OEM and that there are options for us in the event we need to replace.
cheers
 

The Cheese

Way to go Jim. It's quite a task. Well worth it tho. Let us know if anything changes.
 
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And I'm not a member of the " If it ain't broke, then don't fix it " club.
thanks for the clarification on that, Jim.

I actually typed out "or was this just PM" in my previous reply and then deleted it just before sending. I was curious about the possible failure because from what I can tell here there have been very few 40A failures over the years.
 
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Jim Van
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8470
Cheese : I didn't upgrade from a 28 Amp, just replaced a 40 Amp with a 40 Amp. I don't want to take credit for doing a conversion job.

Doug : True, but it was time to clean & grease the swing arm bearings and replace the u-joint, so it wasn't that much extra work. The only failure I remember reading about on this Forum was a failure of the solder joint on the rotor "plate". The owner re-soldered to make the repair.

BTW, at about 50K miles, I replaced the alternator brushes. The old brushes were worn only about a sixteenth of an inch.
 
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Jim Van
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West Michigan
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'98 ST1100
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8470
UPDATE #1 : I now have about 2.450 miles on the new Chinese alternator and it 's still working just fine.

UPDATE #2 : Took a ride up to Quebec over the last several days. Now have over 4,177 miles on the new Chinese alternator and it's still alternating. Rode by a big bull moose standing on the side of the road about 45 Km's north of North Bay, Ontario. Thankfully, he was just standing there looking at us.
 
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Just some poo for the pile..

I installed the same Chinese alternator that is referenced here. I have about 1300 miles on mine so far, no issues. I show the save voltages that Jim Van does, only I am powering a GPS as well as an mp3 player with some overpowered headlights. Time will tell how long the alternators will last.
 
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