ST1300 Alternator Amps

Joined
Oct 20, 2025
Messages
77
Age
56
Location
Singapore
Bike
ST1300
Correct W and Amps for the different year models?

2005 ST1300A Alternator
Output: ~742 W (about 55 A at 14 V).

2009 ST1300A Alternator
Output: ~990 W (about 70 A at 14 V).

Anyone know the output for part number :
Part Number: 31100-MCS-013 (Supersedes 31100-MCS-003) is this about 60Amps?

Refreshing my alternator with 31100-MCS-013 for year 2005
 

Attachments

  • IMG_1970.png
    IMG_1970.png
    582.3 KB · Views: 11
  • IMG_1969.png
    IMG_1969.png
    813.6 KB · Views: 11
  • IMG_1971.png
    IMG_1971.png
    541.8 KB · Views: 11
Correct W and Amps for the different year models?

2005 ST1300A Alternator
Output: ~742 W (about 55 A at 14 V).

2009 ST1300A Alternator
Output: ~990 W (about 70 A at 14 V).

Anyone know the output for part number :
Part Number: 31100-MCS-013 (Supersedes 31100-MCS-003) is this about 60Amps?

Refreshing my alternator with 31100-MCS-013 for year 2005
Not necessarily so. Different alaternator outputs for different countries and markets. Eg my 2006 (A6) UK alternator supplies just under 62 amps.
 
The higher output AMP Alternators are used on Police bikes here in the States,
For all the added equipment they need on patrol.

Unless you plan on adding a serious amount of Christmas lights? to run constantly? you'll do just fine with the OEM Alt.

I suggest you take the Alternator to a shop for testing, if working properly? Then have them install new brushes & bearings. (aka rebuilt)
Don't forget the O-Rings.

 
The higher output AMP Alternators are used on Police bikes here in the States,
For all the added equipment they need on patrol.

Unless you plan on adding a serious amount of Christmas lights? to run constantly? you'll do just fine with the OEM Alt.

I suggest you take the Alternator to a shop for testing, if working properly? Then have them install new brushes & bearings. (aka rebuilt)
Don't forget the O-Rings.

Was contemplating rebuilding it or just get a brand new ones.

I’m impressed for a 20 year old bike, new OEM parts are mostly all still available.
 
Was contemplating rebuilding it or just get a brand new ones.

I’m impressed for a 20 year old bike, new OEM parts are mostly all still available.
Ask a local shop that rebuild Alternators what they charge? and what they change when they rebuild a alternator.

If money is no problem, Spend it-You can't take it with you! :roflmao-2x:
 
Is the alternator part number for STPs different from STAs?
In North America all ST1300's, all models, all model years, use the same part number alternator including the P models, and they are all 742 Watt alternators.
I don't know what was available in other markets but I have never heard anyone ever mention a 990 Watt ST1300 alternator before.
 
13 years ago in my city of a million + population I couldn’t find an alternator rebuilder that could bench test my ST1300 alternator due to the gear drive. Parts were available and they could rebuild it but the shop that I trusted didn’t want to do it because they couldn’t guarantee it would work properly without bench testing it. It wasn’t a lot more expensive at the time just buy a warranteed new one for about $550.
 
Last edited:
I’m impressed for a 20 year old bike, new OEM parts are mostly all still available.
Let's just hope you don't need one of the NLA parts.
Ask a local shop that rebuild Alternators what they charge? and what they change when they rebuild a alternator.

If money is no problem, Spend it-You can't take it with you! :roflmao-2x:
In my neck of the woods finding a shop that rebuilds alternators will take you a while. Last time I had a problem I found a shop in Akron - that was typically filthy, with parts on every horizontal surface and a guy who really knew his stuff and fixed me up with a test in 5 minutes. No charge even when I offered to pay him.

They can always stuff crumpled up dollar bills around him on his bike in the grave before they bury him.
 
15 years ago in my city of a million + population I couldn’t find an alternator rebuilder that could bench test my ST1300 alternator due to the gear drive. Parts were available and they could rebuild it but the shop that I trusted didn’t want to do it because they couldn’t guarantee it would work properly without bench testing it. It wasn’t a lot more expensive at the time just buy a warranteed new one for about $550.
Yes I figured it that much too
 
15 years ago in my city of a million + population I couldn’t find an alternator rebuilder that could bench test my ST1300 alternator due to the gear drive. Parts were available and they could rebuild it but the shop that I trusted didn’t want to do it because they couldn’t guarantee it would work properly without bench testing it. It wasn’t a lot more expensive at the time just buy a warranteed new one for about $550.
I'm rather surprised No one has made a pulley (Adapter tool) so it could be shared amongst the members here??

so any Alternator rebuild shop, can install new Honda parts in their alternator, and be able to bench test it!!

As a mechanic (mostly GL1800's,) I made a Pulley tool, because the GL1800 ALT also has a serrated nose shaft (Spline'd) coming off the Alt Rotor.

Anyone can make one for the ST1300 as well.

You just need the Alternator driven gear shaft. And weld a V-belt pulley to the part of the shaft with the serrated internal splines!!

This is the Alternator driven gear parts. (below)

The third picture shows the shaft that a Pulley could be welded too.

Not a hard process for a DYI-guy with a welder!

The needed shaft is cheap on ebay.

 

Attachments

  • 1.jpg
    1.jpg
    69.6 KB · Views: 4
  • 2.jpg
    2.jpg
    129.4 KB · Views: 5
  • 3.jpg
    3.jpg
    60.8 KB · Views: 4
Back
Top Bottom