Author Topic: Alternator going bad?  (Read 4006 times)

Offline Filmcamera

  • ^ Quintessential Motobricker
  • Posts: 1463
Alternator going bad?
« on: July 24, 2018, 12:01:04 PM »
Hi


I suspect the alternator is on the way out.  It went bad last year and I had it fixed here in CR but now I am getting the charge light coming on at tickover and a nasty noise coming from the general area of the alternator.  My voltmeter shows 11.8v at tickover and even if I rev to 2500 or so it is still only just over 12v, maybe 12.3v or so.


Can anyone confirm that is my issue?


I have already ordered a second hand one from eBay - at $30 I thought it was worth having either way - but would appreciate input in case there is more I should be looking at as well.


Here is a video








  • San Jose, Costa Rica
  • 1991 K100RS 16v ABS1, 2022 Triumph Tiger 900 Rally Pro
Poserbricker

Offline Martin

  • ^ Quintessential Motobricker
  • Posts: 4475
Re: scrotator going bad?
« Reply #1 on: July 24, 2018, 05:14:07 PM »
Either use a screw driver as a stethoscope or buy an automotive one. Then you can determine where the noise is coming from. But I believe your diagnosis is correct. It's not a big job but make sure you have your monkey nuts aligned. A dab of silicone grease helps to hold them in place, and make sure you have the blades of the cups aligned.
Regards Martin.
  • North Lakes Queensland Australia
  • 1992 K75s Hybrid, Lefaux, Vespa V twin.

Offline Filmcamera

  • ^ Quintessential Motobricker
  • Posts: 1463
Re: Alternator going bad?
« Reply #2 on: August 02, 2018, 06:00:25 PM »
The new alternator arrived yesterday morning, I fitted it in the afternoon and went for a great ride today!


100 miles of twisties with a few riding buddies (today is a holiday here) the bike running great.  It did overheat a little on some of the higher, slower, streep climbs, the highest we got was 1 mile above sea level today so I guess it can be forgiven











  • San Jose, Costa Rica
  • 1991 K100RS 16v ABS1, 2022 Triumph Tiger 900 Rally Pro
Poserbricker

Offline Motorhobo

  • +25 years of K75
  • ^ Quintessential Motobricker
  • Posts: 1530
Re: Alternator going bad?
« Reply #3 on: August 03, 2018, 10:05:33 AM »
I'm relieved to see you're actually getting some miles on that bike with all the tribulations you've had with it -- I was getting concerned you were just using it as conversation piece  :beer:
1994/1995 K75 ABS Frankenbike: original engine 136k miles, frame from Gary Weaver (RIP), 173k miles -- Current Odometer: 198k miles
1994 K75 since 2013, 82,000 mi (19k mine) w/California Sidecar Friendship II Sidecar & Black Lab 'Miss B' - RIP

Past: 1974 Honda 550/4 (first bike), 1994 K75 (sold), 1995 K75 ABS (parts bike), Sidecar Dog & Best Bud 'Bo' - RIP

Offline Laitch

  • Faster than a speeding pullet
  • Administrator
  • ^ Quintessential Motobricker
  • Posts: 11299
Re: Alternator going bad?
« Reply #4 on: August 03, 2018, 10:39:20 AM »
The new alternator arrived yesterday morning, I fitted it in the afternoon and went for a great ride today!
:2thumbup:
  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles

Offline Filmcamera

  • ^ Quintessential Motobricker
  • Posts: 1463
Re: Alternator going bad?
« Reply #5 on: August 03, 2018, 06:41:06 PM »
Quote
[size=78%]I'm relieved to see you're actually getting some miles on that bike with all the tribulations you've had with it -- I was getting concerned you were just using it as conversation piece[/size]


Oh I manage to do ok on her most of the time, with the alternator issue the bike was off the road for two weeks which is the longest it has been out of action for about a year.  I have put about 3,000 miles on it since getting it running again. Not a huge amount but not bad.  When the dry season comes round again I plan to do some multi day trips - or at least a couple of 400 mile days which is about the max you can do in CR due to the roads etc.


Al in all it is running very well, even the brakes are binding less now that the pads are being worn down.
  • San Jose, Costa Rica
  • 1991 K100RS 16v ABS1, 2022 Triumph Tiger 900 Rally Pro
Poserbricker

Tags: alternator 16v