Author Topic: 79 sportster 1000. no spark, power to coils  (Read 554 times)

0 Members and 1 Guest are viewing this topic.

Offline mein207

  • Member
  • Posts: 1
  • Country: us
79 sportster 1000. no spark, power to coils
« on: April 14, 2017, 04:55:49 PM »
well, I picked her up a little while ago. been sitting for a long time. changed fluids, plugs and the normal stuff. ran ok, but not what I would like it to be. changed the front tire, fired it up. ran for a couple minutes and died. now no spark from coil. has primary power and the points are opening and closing, power to the points. checked plug gap,point gap, ignition timing, all show as they are supposed to. I suspect coil but don't want to just throw parts at it. ive looked online and there seems to be different ideas on how to properly check it. I know people don't seem to like this year bike, but I really like it for some reason. any help or ideas will be greatly appreciated. thanks, vince

Offline Panzer

  • Shed Master
  • Full Member
  • Posts: 11151
  • Country: us
  • Live one day at a time.
Re: 79 sportster 1000. no spark, power to coils
« Reply #1 on: April 15, 2017, 04:36:27 AM »
Lay a plug on the head with wire connected.
Ignition on and set the point closed.
Open and close the points with a piece of wood. (a pencil will do)
Try it several times.
You should get spark at the plug, you might even hear the spark snap....... if you don't, it's the coil.
As a Courtesy, post you findings.
You don't have to shovel sunshine ..... let's ride.

Offline Hossamania

  • Road Glide Lover
  • Site Supporter
  • Full Member
  • *****
  • Posts: 14409
  • Country: us
  • 'Cuz ugly bikes need love too.
Re: 79 sportster 1000. no spark, power to coils
« Reply #2 on: April 15, 2017, 10:51:52 PM »
Whenever I have problems with a point ignition, I change the capacitor. A cheap place to start.
No shirt, no shoes, but I still get service.
Why? Girl, look at this body!

Offline FSG

  • BrisVegas in Oz
  • Administrator
  • Full Member
  • *****
  • Posts: 16804
  • Country: au
  • BrisVegas
Re: 79 sportster 1000. no spark, power to coils
« Reply #3 on: April 15, 2017, 11:51:41 PM »
the capacitor is in parallel with the points and it serves two purposes

1 - it reduces contact wear/pitting by quenching the contact arc when the points open

2 - provides the High Voltage ground for the secondary side of the coil

with a bad or missing capacitor you'll have no spark at the plugs
 

Offline rider7816

  • Full Member
  • Posts: 91
  • Country: us
Re: 79 sportster 1000. no spark, power to coils
« Reply #4 on: May 08, 2017, 05:05:49 AM »
Whenever I have problems with a point ignition, I change the capacitor. A cheap place to start.

Yea, what Hoss said!  Or you can do away with the points and go electronic to get rid of all of your ignition headaches.

Frank

Offline wreck74

  • Full Member
  • Posts: 215
  • Country: 00
Re: 79 sportster 1000. no spark, power to coils
« Reply #5 on: June 09, 2017, 03:18:48 PM »
It's not a capacitor, it's a condenser, it is a shock absorber for the points, (keeps them from burning up) yes they go bad, do what panzer said.

Offline FSG

  • BrisVegas in Oz
  • Administrator
  • Full Member
  • *****
  • Posts: 16804
  • Country: au
  • BrisVegas
Re: 79 sportster 1000. no spark, power to coils
« Reply #6 on: June 09, 2017, 05:44:13 PM »
Quote
It's not a capacitor, it's a condenser

in the early days they were called condensers, these days they are called capacitors, capacitor, condenser, same thing, call them what you like

Offline Hossamania

  • Road Glide Lover
  • Site Supporter
  • Full Member
  • *****
  • Posts: 14409
  • Country: us
  • 'Cuz ugly bikes need love too.
Re: 79 sportster 1000. no spark, power to coils
« Reply #7 on: June 09, 2017, 09:35:13 PM »
I actually did mean condenser. Haven't worked with them for a while, but still remember to set points at .019", about the with of the cardboard in an old matchbook. Not sure of the new matchbooks....
No shirt, no shoes, but I still get service.
Why? Girl, look at this body!

Offline Wicked

  • Site Supporter
  • Full Member
  • *****
  • Posts: 1817
  • Country: ca
Re: 79 sportster 1000. no spark, power to coils
« Reply #8 on: June 10, 2017, 06:56:47 AM »
....and use the striker to clean the plugs  :wink: !  Young folks don't know what they're missing...  :hyst:

...sorry to get off post...

Offline wreck74

  • Full Member
  • Posts: 215
  • Country: 00
Re: 79 sportster 1000. no spark, power to coils
« Reply #9 on: June 15, 2017, 09:42:03 AM »
0.32 for the plugs and 0.15-16 for the points, 0.19 is kinda wide.

Offline Hal64hd

  • Full Member
  • Posts: 116
Re: 79 sportster 1000. no spark, power to coils
« Reply #10 on: June 15, 2017, 01:32:00 PM »
I have seen in the past, the leads to the points on the wrong side of the insulator and cause the ignition to be constantly grounded.

Offline Hossamania

  • Road Glide Lover
  • Site Supporter
  • Full Member
  • *****
  • Posts: 14409
  • Country: us
  • 'Cuz ugly bikes need love too.
Re: 79 sportster 1000. no spark, power to coils
« Reply #11 on: June 16, 2017, 08:18:45 AM »
0.32 for the plugs and 0.15-16 for the points, 0.19 is kinda wide.

That makes sense with that charging and electrical system. Automobiles usually have a stronger system. That's what I was basing my old measurements off of.
No shirt, no shoes, but I still get service.
Why? Girl, look at this body!