Are you still running 28 Amp. Alternator?

Joined
Jul 18, 2012
Messages
48
Location
NJ
STOC #
8924
A recent poster commented that by now most of the 28 Ampers have been upgraded to 40 Ampers or long dead and gone. Is that so, are you still running your 28 Amper?
I for one am still using a 28 Amper.:06biker:
 
Joined
Oct 6, 2011
Messages
369
Location
Indiana
STOC #
9050
Yep, my 95' still has the 28 in it. Have run a vest, gloves and radar for years without any issues.
120,000+ miles.
 
Last edited:
Joined
Aug 10, 2015
Messages
2,029
Location
Fort Worth, Texas
Bike
91 ST1100/06 ST1300
Still have the 28 amp unit in my 1991. Found a spare from a 5000 mile plus wreck. Continuity checks out and there is no evidence of oil leaks or overtemp anywhere. I packed it away with a set of o-rings just in case. It will remain stock until I have no alternative.
 
Joined
Mar 20, 2016
Messages
1,201
Location
Auckland, New Zealand
Bike
2005 ST1300
STOC #
8901
I've only owned my 1990 since April last year but have put on 19,000 km since then to bring it to 110000km. It still has the 28A alternator, and I have carefully cleaned and greased all connectors, and there are no signs of any heat-related damage. I suffer from maintenance OCD. It has always has a slight oil weep from the end cap, enough to be visible on the casing but not enough to drip off. I have a voltmeter installed and have moved to all LED lighting, with just heated grips as farkles, and the voltage is rock-solid at around 14.2V.
 
Joined
Sep 23, 2012
Messages
42
Location
near ST Louis
Bike
2005 FJR1300A
STOC #
8658
My '91 is still running a 28 amp. The owner before me replaced the stator. After I got it the VRR died because of heat and corrosion. I did the red wire upgrade and went further with some custom stuff. I've put 80k miles on it since then with no problems, and I run a vest only. The bike is at 146k miles.
 

jim 91 st

Jim 91 ST1100
Joined
May 10, 2008
Messages
46
Location
Holland, Michigan
Bike
91 ST1100
I have a 91 with 121k miles and added a voltmeter this past Spring. Charging nicely, no issues at all. My ST is my daily rider and has given me zero problems in 10 years of ownership, but I am wondering about the wisdom of taking it on a 3000 mile trip into Mexico next spring on the old alternator. Everything else is in great shape and has been very well maintained.
 
Joined
Jun 3, 2006
Messages
3,512
Location
British Columbia
Bike
2021 RE Meteor 350
The main point, seemingly proven here, is that a 28 amp unit will give a long life, if you don't ask too much of it. It only has about 10 amps to spare and just adding auxiliary lighting (non LED) can wipe out most of that reserve. Add more farkles and you cause overheating, leading to problems in the wiring and the alternator windings as well.

Having said that, my '95 went 175,000 km. with just higher wattage headlight bulbs (55/60W) and an electric vest before it failed.
 

bdalameda

PaleoCyclist
Joined
Jan 13, 2009
Messages
2,423
Age
67
Location
Salinas, California
Bike
Africa Twin
It is my understanding that in the UK the 28amp alternator is preferred over the 40amp on the St1100. This is due to the very rainy and wet conditions where the 40 amp alternator has had issues from moisture in the windings and causing the alternator to lock up. The 28amp alternator seems to be immune to this. Also major issues with swingarms rusting through in the UK that is rarely seen here in the US.
 
Top Bottom