Alternator Rebuilding Services for 28 AMP Alternators

[Stylo Steve]

Does anyone have any knowledge of anyone who can rebuild a 28 amp alternator for 1995 ST1100? I have everything inventoried to replace my current 28 amp alternator with a 40 amp alternator but would like to stay with the 28 amp alt if possible. Or are there any members on the STOC who have a new or low-time alternator that they would like to sell?

 

[kiltman]

With regards to rebuilding the 28 amp alternator to the best of my knowledge there hasn’t been a successful rebuild. The stumbling block has been the seal from where the wires exit the alternator.
There may be a used one that has some life left in it, but again it’s prone to the seal failing.
For the most part, the procedure involved in swapping out a 28 amper for another 28 amper is close to that of upgrading to the 40 amp unit. You will still need to remove the fuel tank, the rear wheel and swing arm to get at the alternator.
Given the cost of acquiring a generic 40 amp unit from eBay ($135) and the future dependability of the conversion, I strongly recommend that you pursue upgrading.

 

[Oldbikefixr]

Check out your local wrecking yards for a low mile early model wreck. If you do find one, check the wiring exit for signs of oil leakage, if so...pass. Either way you're going to have to remove her rear end, may as well do the upgrade.

 

[Stylo Steve]

With regards to rebuilding the 28 amp alternator to the best of my knowledge there hasn’t been a successful rebuild. The stumbling block has been the seal from where the wires exit the alternator.
There may be a used one that has some life left in it, but again it’s prone to the seal failing.
For the most part, the procedure involved in swapping out a 28 amper for another 28 amper is close to that of upgrading to the 40 amp unit. You will still need to remove the fuel tank, the rear wheel and swing arm to get at the alternator.
Given the cost of acquiring a generic 40 amp unit from eBay ($135) and the future dependability of the conversion, I strongly recommend that you pursue upgrading.

Thank you for the information regarding the seal. I've got the bike completely disassembled and ready to place an alternator in it so I guess the best thing to do would be to take your advice and move forward with the 40 amp install.

 

[Stylo Steve]

Check out your local wrecking yards for a low mile early model wreck. If you do find one, check the wiring exit for signs of oil leakage, if so...pass. Either way you're going to have to remove her rear end, may as well do the upgrade.

Thank you for your input and I'll be performing the 40 amp upgrade this weekend. Hopefully, everything will go as smoothly as a mayonnaise sandwich and I can make a trip to Pie Town New Mexico mid-September.

 

[wjbertrand]

There were a couple of folks who tried rebuilding the 28A years ago only to have it fail again very quickly and in at least one case was DOA and never worked at all.

I can’t for the life of me think why one would want to stick with the 28A when the 40A upgrade is such an improvement!

 

[kiltman]

I can’t for the life of me think why one would want to stick with the 28A when the 40A upgrade is such an improvement!

One of the reasons is that it's enclosed and protected and cooled by oil. If the original was a higher amperage from day one it might have survived. Other than that the 40 amp capacity is far superior and even then some of us could use more juice.

 

[snowworks]

Does anyone have any knowledge of anyone who can rebuild a 28 amp alternator for 1995 ST1100? I have everything inventoried to replace my current 28 amp alternator with a 40 amp alternator but would like to stay with the 28 amp alt if possible. Or are there any members on the STOC who have a new or low-time alternator that they would like to sell?

Stylo, I am working on a 93 ST with charging problem. Where did you get the 40 amp parts?? I have been searching and all of them have been the 96 and up 40 amp. Lots of them out there. The oil leak is also a problem on mine. Did you check the 3 yellow wires with an ohm meter?? Mine is about .6 ohm with about 2.3 ohm to ground. I do get AC volts out of it. I might have a rectifier problem. I do not care if it is a 28 amp or 40 just need it to work. I am going to post on mine now..

 

[Stylo Steve]

I ordered a plate kit from a gentleman that advertised them on ebay. I think he has advertised them on this site as well at one time. I had a friend of mine who is an electrial engineer redo all of the wiring so I'm not goin to be much help to you in the electrical department.

 

[wjbertrand]

One of the reasons is that it's enclosed and protected and cooled by oil. If the original was a higher amperage from day one it might have survived. Other than that the 40 amp capacity is far superior and even then some of us could use more juice.

Understood, besides the higher output the 40A has a better reliability record as well though. This is not to mention the frequent oil leaks through the casing where the harness exits. I think the 28A one is Cooked by the oil as much as it is cooled!