1991 ST - 40 AMP upgrade

So I found everything to do the 40 amp upgrade on my 1991. It is pushing 70k miles so I guess I am on borrowed time. Everything for the 40 amp is coming from a 1999 with less than 50k miles. Below is a picture of what I am getting. Not exact parts but a picture of the parts needed.

I cannot find these things anywhere except out of the UK. So in all the expert opinions out there is $400 including shipping a fair price?

Brad, I believe the UK 40 amp alternators frequently have problems from road salt etc. Many there prefer the 28's. Just something to check out. Not sure about the price. New may not be a heck of a lot more?
Gonna make a video of the upgrade by any chance? I keep putting mine off at, 103k, but do have all the parts.

Have you gone to the List and got the tool kit for the swap. Have you talked to John O? He is both on here and over on the List (ST-riders.net) Click on the link in my Sig. block

Chuck, I have looked at the list of tools and I have everything or can easily make it. But thanks for the info. Since so many have done this upgrade and have documented the process, I find that it does not look difficult but more time consuming to get to where you need to get go to do the work. I just did the drive shaft maintenance 6 weeks ago so pulling all of that apart I am familiar with. I did it to both bikes. I should have thought about this then. I find the Lewis Pin a very interesting device. Who ever came up with that is genius. Dead simple but effective and easy to use.

Dean. This alternator is from the southern US and the equipment is clean looking. I am not sure if I will video this or not. The issue I have is that once I start I go until it is done and don't take much time out for anything else. The beauty is that I also have a 2000 for reference, and that currently have the tank out and carbs off so I am taking pictures of wire routing and such before I put it back together. If you buy everything new it is a lot more.

The price might be a little high, but everything appears to be there except for a little cable between the fuseblock and relay (or direct to battery). Also, you're getting the 40amper alt shaft assy which is a plus. Price out everything on Service Honda and see if you can negotiate the price. My rule of thumb would be to not pay more than 50% of new for used part. And generally, that all electrical parts have passed a bench test. I see a notch in the alt cover which indicates it was a new stock unit that was used in a previous upgrade, FWIW. You might ask what is the total mileage on the that particular alternator. JMO

Let me know if you want to borrow the upgrade kit.

Regards, John
via iPhone 4S

John. Thanks. That picture is just an example I sent the place so they could gather the correct parts from the bike. But thanks for the input.

Here's a dumb question but... so I just pulled out my 28 amp out of the bike bought a used 40 amp (really good condition )... now what ??? No one ever explains this part??? The heck did I do with both alternators??????

Nanuk said:

Here's a dumb question but... so I just pulled out my 28 amp out of the bike bought a used 40 amp (really good condition )... now what ??? No one ever explains this part??? The heck did I do with both alternators??????

Click to expand...

If there is a question there, dumb or not, I'm not getting it . . . ?

In other words the 28amp alternator is off the bike on the work bench... The used 40 amp is next to it how do i Frankenstein them together???? I was able to take apart the 28amp but the 40amp is not coming apart and i don't see how to fit them together

Grabcon said:

So I found everything to do the 40 amp upgrade on my 1991. It is pushing 70k miles so I guess I am on borrowed time. Everything for the 40 amp is coming from a 1999 with less than 50k miles. Below is a picture of what I am getting. Not exact parts but a picture of the parts needed.

I cannot find these things anywhere except out of the UK. So in all the expert opinions out there is $400 including shipping a fair price?

Click to expand...

Check out the on-line Honda part sources for your 40 amp alternator. Partzilla has a brand new Honda 40 amp (just the alternator) listed for $411. Why risk doing the job over again next week with an unknown life remaining used unit for nearly the same price?

Nanuk said:

In other words the 28amp alternator is off the bike on the work bench... The used 40 amp is next to it how do i Frankenstein them together???? I was able to take apart the 28amp but the 40amp is not coming apart and i don't see how to fit them together

Click to expand...

This should help you.

http://www.st-riders.net/index.php?topic=942.0

Here's another useful page.

http://koczarski.com/mmartin/Alt.htm

But i have the alternator do i need more parts??? The brushs are almost New in the 40amp alternator....

Nanuk said:

But i have the alternator do i need more parts??? The brushs are almost New in the 40amp alternator....

Click to expand...

You don't need more parts, but you do use some of the parts from the 28 amp base to mate up the 40 amp alternator. Read through those links I posted and the mud should clear.

You should be OK with the salvage 40amp alternator. You should have also asked for the big part that plugs into the engine: the Alternator Shaft Assembly. Now you'll have to assemble the 40amper version with parts from the old 28amper's Alt Shaft Assy and some new parts. Read the links posted and things will begin to make sense to you. Here's a picture of the old and new parts for an upgrade:
http://www.st-riders.net/coppermine/displayimage.php?album=22&pid=998#top_display_media

Edit: Do NOT disassemble the 40amp alternator unit itself! That's not necessary!

John
via iPhone 6

John OoSTerhuis said:

You should be OK with the salvage 40amp alternator. You should have also asked for the big part that plugs into the engine: the Alternator Shaft Assembly. Now you'll have to assemble the 40amper version with parts from the old 28amper's Alt Shaft Assy and some new parts. Read the links posted and things will begin to make sense to you. Here's a picture of the old and new parts for an upgrade:
http://www.st-riders.net/coppermine/displayimage.php?album=22&pid=998#top_display_media

Edit: Do NOT disassemble the 40amp alternator unit itself! That's not necessary!

John
via iPhone 6

Click to expand...

Ahhh Now i get it (it just turned on) dang if I only new what i need to get B4 hand would have had order the parts and had them ready to install and been riding by the end of the day.. I'll start a thread with the pic's i took on how to do the upgrade with a used alternator...