« previous next »
Pages: [1]   Go Down

Author Topic: 1971 CB 500 Four Keep blowing fuses  (Read 2542 times)

0 Members and 1 Guest are viewing this topic.

Offline 1978CB750

  • Full Member
  • *
  • Posts: 5
1971 CB 500 Four Keep blowing fuses
« on: September 30, 2011, 06:09:39 PM »
1971 Honda CB500 4

I charge the one year old battery on the trickle charger over night. The bike starts fine and rides fire for about 10 miles then the fuse blows and the battery is totally dead. Happened a few times now.

Any hints of what I should check?
Logged

Offline MoMo

  • Really Old Timer ...
  • *******
  • Posts: 8,271
  • Ride like you're invisible
Re: 1971 CB 500 Four Keep blowing fuses
« Reply #1 on: September 30, 2011, 06:19:17 PM »
The first thing I would check is the fuse box, either for corroded terminals  or melted wires as a result of the corrosion...Larry
Logged

Offline TwoTired

  • Really Old Timer ...
  • *******
  • Posts: 21,802
Re: 1971 CB 500 Four Keep blowing fuses
« Reply #2 on: September 30, 2011, 06:20:57 PM »
Check to see if after 40 years the stock wire diagram is still relevant.

Rather than stating the battery is dead, report the battery voltage that leads you to make such a report.

After installing the charged battery, and it has rested for 2 hours, report the battery voltage before starting and then after starting, at Idle and 1000 RPM increment up to 5000 RPM.

Report the fuse rating you are using in the bike.

Inspect the wires around the steering neck for fraying damage.

Cheers,
Logged
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

72500john

  • Guest
Re: 1971 CB 500 Four Keep blowing fuses
« Reply #3 on: September 30, 2011, 06:23:11 PM »
check your charging system..maybe a case of over charging? which can be caused by dirty connections. aka a dirty connection will show a low battery voltage at the montoring input to your regulator due to voltage drop across the bad connections.  the low voltage seen at the regulator will  result in overvoltage/current and a boiled/fried battery. trust me i know.
Logged

Offline HondaMan

  • Someone took this pic of me before I became a
  • Really Old Timer ...
  • *******
  • Posts: 14,101
  • ...not my choice, I was nicknamed...
    • Getting 'em Back on the Road
Re: 1971 CB 500 Four Keep blowing fuses
« Reply #4 on: September 30, 2011, 09:25:03 PM »
This can also come from a shorted rectifier.
Logged
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com

Offline Danno

  • Hot Shot
  • ***
  • Posts: 715
  • 74 CB550,75 GL1000,76 KZ400,77 GL1000,73 CB750
Re: 1971 CB 500 Four Keep blowing fuses
« Reply #5 on: September 30, 2011, 09:35:52 PM »
I am betting on the rectifier too but two tired has a lot of good things to check to be certain
Logged
when you own a motorcycle the wife does not have to find you handy she just has to find you
Pages: [1]   Go Up
« previous next »