IndyRob
Site Supporter
Hi all. I just completed the upgrade of the alternator on my ’93 ST with 65K miles and wanted to share some experiences/lessons learned. First off, as others have said before me THANK YOU THANK YOU THANK YOU to all who have documented this procedure with text, videos, etc. and to John Oosterhaus for the "helpline" when I got stuck a few times.
I read all of the notes and watched the videos many times before starting in. Overall the process went very well, but there were a few times I was “challenged” by my ST and I would say this is not an undertaking for anyone who does not have a good set of metric tools and a comfortable and well lit place to work. I spent probably 20 hours overall but I did clean the heck out of every part as I took things apart. I found the CRC Professional Grade Parts Cleaner (blue spray can) worked best for cleaning pretty much everything.
This is the first time my 30 year old bike has been disassembled at anywhere near this level so I was quite concerned about encountering rusted or stuck fasteners. Fortunately, everything came apart OK but I was careful to use only 6 point sockets on every bolt. The biggest area of concern were the 3 socket head bolts that hold the old stator to the drive case, since I could not get a perfectly straight angle on 2 of the 3. I was really concerned about stripping these, so I did spray them with Aero Kroil (if you have not used this stuff before…. It is FANTASTIC for loosening stuck/rusted bolts!! Not cheap, but the stuff just WORKS).
My first “hang up” was when I installed the newly built drive mechanism (using the parts from the old one and a new base plate). The two gears were perfectly aligned with the Lewis Pin fully inserted, but when I inserted the new drive into the engine the base plate would not meet up with the engine housing… I had about 1/8” gap. I was pretty confident that the gears were meshing fine. With encouragement/guidance from John O and the gentleman who had just done this (and sent me the upgrade kit) I carefully snugged the new baseplate the rest of the way into the engine using my smallest ¼” drive socket to ensure I didn’t strip anything.
My second “hang up” was re-installing the swing arm. I read all the instructions and notes available, but when it came time to re-install the swing arm (and drive shaft) I figured I would have to hold the drive shaft U-joint onto the transmission spline or else it would fall out. Well, the swing arm WILL NOT align into the two side holes on the frame with the drive shaft already installed in the transmission spline! It does not clear the right side of the frame by the smallest of margins. After messing with this for almost an hour (and cursing quite a bit!) I finally just let the drive shaft fall into the swing arm, installed the swing arm pins and then lo and behold I was able to get the U-joint splines onto the transmission rod with a little fiddling of the drive shaft from the rear of the swing arm! It also helps to have the bike in gear at this point so the transmission shaft does not rotate while you are trying to get the U joint aligned onto it.
Some points about the process as documented in the write up:
I never did touch the shifter bolt… (the notes from Mike Martin said he didn’t either..) and had no issues. I also do not think it’s necessary to remove the 2 bolts from the transmission housing since it seemed like my new alternator never got close to these using the technique of inserting the new alternator in the videos online. But I definitely DID have to bend the small bracket that held one of the rear brake line clamps up about 45 degrees to get the alternator to clear. That video was awesome, and I had the new alternator in within 3 minutes!
There are 3 hoses that need to be either extended or replaced with longer ones. The sizes were not mentioned in the notes but they are 1 X 3/16” inside diameter hose and 2 X 1/4” ID hoses. You will also need to purchase male-male adapters if you are using extensions as I did. I found an assortment pack of these that included 2 each of several sizes at my local AutoZone for $7.
For the fuse from the 12V alternator main to the battery, I wound up just soldering in an inline fuse holder with 10AWG wire from Amazon ($11 for a package of 6!) and used a 50A blade fuse (also Amazon, $5 for a pack of 10). Seemed much cleaner and cheaper than some of the other options I read about.
Finally, I also used this tear down to do some other basic maintenance like replacing the air, oil and fuel filters, rear brake pads, and the engine and rear drive oil (you are in there anyway… so why not!!).
In the end my ST is now running like new and I am getting a steady 14.48V at the battery from idle on up. She’s ready for another 30 years I hope!
Cheers!
I read all of the notes and watched the videos many times before starting in. Overall the process went very well, but there were a few times I was “challenged” by my ST and I would say this is not an undertaking for anyone who does not have a good set of metric tools and a comfortable and well lit place to work. I spent probably 20 hours overall but I did clean the heck out of every part as I took things apart. I found the CRC Professional Grade Parts Cleaner (blue spray can) worked best for cleaning pretty much everything.
This is the first time my 30 year old bike has been disassembled at anywhere near this level so I was quite concerned about encountering rusted or stuck fasteners. Fortunately, everything came apart OK but I was careful to use only 6 point sockets on every bolt. The biggest area of concern were the 3 socket head bolts that hold the old stator to the drive case, since I could not get a perfectly straight angle on 2 of the 3. I was really concerned about stripping these, so I did spray them with Aero Kroil (if you have not used this stuff before…. It is FANTASTIC for loosening stuck/rusted bolts!! Not cheap, but the stuff just WORKS).
My first “hang up” was when I installed the newly built drive mechanism (using the parts from the old one and a new base plate). The two gears were perfectly aligned with the Lewis Pin fully inserted, but when I inserted the new drive into the engine the base plate would not meet up with the engine housing… I had about 1/8” gap. I was pretty confident that the gears were meshing fine. With encouragement/guidance from John O and the gentleman who had just done this (and sent me the upgrade kit) I carefully snugged the new baseplate the rest of the way into the engine using my smallest ¼” drive socket to ensure I didn’t strip anything.
My second “hang up” was re-installing the swing arm. I read all the instructions and notes available, but when it came time to re-install the swing arm (and drive shaft) I figured I would have to hold the drive shaft U-joint onto the transmission spline or else it would fall out. Well, the swing arm WILL NOT align into the two side holes on the frame with the drive shaft already installed in the transmission spline! It does not clear the right side of the frame by the smallest of margins. After messing with this for almost an hour (and cursing quite a bit!) I finally just let the drive shaft fall into the swing arm, installed the swing arm pins and then lo and behold I was able to get the U-joint splines onto the transmission rod with a little fiddling of the drive shaft from the rear of the swing arm! It also helps to have the bike in gear at this point so the transmission shaft does not rotate while you are trying to get the U joint aligned onto it.
Some points about the process as documented in the write up:
I never did touch the shifter bolt… (the notes from Mike Martin said he didn’t either..) and had no issues. I also do not think it’s necessary to remove the 2 bolts from the transmission housing since it seemed like my new alternator never got close to these using the technique of inserting the new alternator in the videos online. But I definitely DID have to bend the small bracket that held one of the rear brake line clamps up about 45 degrees to get the alternator to clear. That video was awesome, and I had the new alternator in within 3 minutes!
There are 3 hoses that need to be either extended or replaced with longer ones. The sizes were not mentioned in the notes but they are 1 X 3/16” inside diameter hose and 2 X 1/4” ID hoses. You will also need to purchase male-male adapters if you are using extensions as I did. I found an assortment pack of these that included 2 each of several sizes at my local AutoZone for $7.
For the fuse from the 12V alternator main to the battery, I wound up just soldering in an inline fuse holder with 10AWG wire from Amazon ($11 for a package of 6!) and used a 50A blade fuse (also Amazon, $5 for a pack of 10). Seemed much cleaner and cheaper than some of the other options I read about.
Finally, I also used this tear down to do some other basic maintenance like replacing the air, oil and fuel filters, rear brake pads, and the engine and rear drive oil (you are in there anyway… so why not!!).
In the end my ST is now running like new and I am getting a steady 14.48V at the battery from idle on up. She’s ready for another 30 years I hope!
Cheers!
May you have many pleasurable miles and years with your ST.