Antique Engines and Old Iron
[Home] - [HELP] - [Forums] - [Groups] - [Classified Ads] - [Subscribe] - [Books] - [Sponsors] -

Go Back   SmokStak > SmokStak® Antique Engine Community > Magnetos, Ignition Coils and Spark Plugs
Forgot Password? Join Us!

Notices

Magnetos, Ignition Coils and Spark Plugs Discussion about magnetos, buzz coils, spark plugs, ignitors and low tension coils.

Magnetos, Ignition Coils and Spark Plugs

Rebuilt Wico OC, intermittent spark


this thread has 6 replies and has been viewed 385 times

Reply
 
Thread Tools Display Modes
  #1  
Old 10-17-2019, 09:49:01 PM
con-rad con-rad is offline
Registered
 
Join Date: Nov 2012
Location: Guilford, Connecticut
Posts: 548
Thanks: 66
Thanked 416 Times in 201 Posts
Default Rebuilt Wico OC, intermittent spark

Hey all,

Recently rebuilt two OC's with new coils and condensers. The first one I rebuilt will make a 5/8" spark reliably and usually jump a 3/4" gap. The second one I did will only jump 1/2", and even then won't fire every time. I cleaned and filed the points several times and re-adjusted the points gap so they just start to open with the armature 3/32" from the cores. All the electrical connections on the primary and secondary and wire brushed nice and clean and don't have excessive resistance as checked with a multimeter. Am I missing something, or perhaps the magnets are just a little weaker on this one?

Thanks,

connor
Reply With Quote
The Following User Says Thank You to con-rad For This Post:
Sponsored Links
  #2  
Old 10-18-2019, 06:38:41 AM
cobbadog cobbadog is offline
Registered
 
Join Date: Aug 2009
Location: Coopernook. N.S.W. Australia
Posts: 1,947
Thanks: 3,481
Thanked 881 Times in 585 Posts
Default Re: Rebuilt Wico OC, intermittent spark

When you say you don't have 'excessive resistence' how much are you talking?
Is the magneto completely oil free inside and all wires insulated properly so that a spark cannot leak to ground?
What point gap are you using? SOmetimes like this when you work on identical magnetos they end up being totally different. Coils may be slightly different and then that makes a difference too. The same for condensors, might have a slightly different value and give different result.
I would start again and double check all your readings on the new parts and ensure they are within spec. Remove the points and clean under them and clean and re-clean the points and then gap them. Sometimes coils can be a bit faulty even from new and is why if possible they should be checked out on a test bench or use a machine to check the coil first, then heat it using power and re check after 5 - 10 minutes while the coil is warm. If there is a drop in readings or performance this is your problem.
Reply With Quote
The Following User Says Thank You to cobbadog For This Post:
  #3  
Old 10-18-2019, 07:33:54 AM
Kirk Taylor Kirk Taylor is offline
Registered
 
Join Date: Nov 2004
Location: Bedford, PA
Posts: 967
Thanks: 0
Thanked 615 Times in 362 Posts
Default Re: Rebuilt Wico OC, intermittent spark

Quote:
Originally Posted by con-rad View Post
Hey all,

Recently rebuilt two OC's with new coils and condensers. The first one I rebuilt will make a 5/8" spark reliably and usually jump a 3/4" gap. The second one I did will only jump 1/2", and even then won't fire every time. I cleaned and filed the points several times and re-adjusted the points gap so they just start to open with the armature 3/32" from the cores. All the electrical connections on the primary and secondary and wire brushed nice and clean and don't have excessive resistance as checked with a multimeter. Am I missing something, or perhaps the magnets are just a little weaker on this one?

Thanks,

connor
Conner,

If you haven't done it already, either swap the cover from the "good" magneto or remove the cover and check the spark from contact to contact just in case you might have a bad high tension terminal. If the cover is off, you also may be able to see if it's sparking to ground from someplace it shouldn't.
Reply With Quote
The Following User Says Thank You to Kirk Taylor For This Post:
  #4  
Old 10-19-2019, 11:19:21 AM
mmcdonald mmcdonald is offline
Subscriber
 
Join Date: Jun 2006
Location: Jefferson, Georgia, USA
Posts: 669
Thanks: 21
Thanked 240 Times in 214 Posts
Default Re: Rebuilt Wico OC, intermittent spark

Haven't worked on one of those in awhile but if I'm thinking of the right mag the armature not breaking cleanly every time can cause intermittent spark similar to the EK mag. Slop in the slide pin/armature. Just another thought.
__________________
info@mcdonaldcarb.com
Reply With Quote
The Following 2 Users Say Thank You to mmcdonald For This Post:
  #5  
Old 10-19-2019, 08:32:15 PM
con-rad con-rad is offline
Registered
 
Join Date: Nov 2012
Location: Guilford, Connecticut
Posts: 548
Thanks: 66
Thanked 416 Times in 201 Posts
Default Re: Rebuilt Wico OC, intermittent spark

By excessive resistance, i mean that each connection was no more than an ohm. All the wires inside are new and soldered on, with the exception of the factory screw terminals.

the points gap is adjusted so they just start to open with the armature 3/32" from the cores.

I checked the armature guide play, it is the same between the so-so mag and the good one.

Good thought on the cover, i'll try swapping them. I did clean the spring contacts, but i'll try changing it out anyway.

Connor
Reply With Quote
The Following User Says Thank You to con-rad For This Post:
  #6  
Old 10-20-2019, 10:24:24 AM
Mitch Malcolm Mitch Malcolm is offline
Subscriber
 
Join Date: Sep 2005
Location: Ottertail, Minnesota, USA
Posts: 627
Thanks: 774
Thanked 595 Times in 320 Posts
Default Re: Rebuilt Wico OC, intermittent spark

Kirk beat me to it the lead out towers can leak off some voltage without being a complete path to ground same as the EK and PR Wico's and for a shameless plug they are available at and made by Lightning Magneto
Reply With Quote
The Following User Says Thank You to Mitch Malcolm For This Post:
  #7  
Old 10-29-2019, 10:41:57 PM
Tony Page's Avatar
Tony Page Tony Page is offline
Subscriber
 
Join Date: Nov 2004
Location: South Carolina
Posts: 37
Thanks: 0
Thanked 14 Times in 10 Posts
Default Re: Rebuilt Wico OC, intermittent spark

Quote:
Originally Posted by mmcdonald View Post
Haven't worked on one of those in awhile but if I'm thinking of the right mag the armature not breaking cleanly every time can cause intermittent spark similar to the EK mag. Slop in the slide pin/armature. Just another thought.
Had an EK that was driving me crazy. Found that guide pin on the armature had a very slight bend.
Reply With Quote
The Following User Says Thank You to Tony Page For This Post:
Reply

Bookmarks


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

F o r u m Jump

Similar Threads Chosen at Random
Thread Thread Starter F o r u m Replies Last Post
Onan 4.0 cck intermittent no spark problem. Martelli D Onan Generators 4 02-04-2019 08:22:46 PM
Bosch DU 4/2 - - intermittent spark on one circuit Pete LaBelle Magnetos, Ignition Coils and Spark Plugs 7 11-21-2018 04:21:33 PM
Onan CCKB intermittent spark phrankndonna Onan Generators 28 06-03-2012 04:06:10 AM
Intermittent spark on Wico EK Tom Jamboretz Magnetos, Ignition Coils and Spark Plugs 2 10-19-2010 02:15:13 PM
B&S 5S - Intermittent Spark - Newbie Question Gauge Small Air Cooled Gasoline Engines 15 11-22-2006 12:39:48 PM


Use "Ctrl" mouse wheel to change screen size.
All times are GMT -4. The time now is 04:21:58 AM.

Smokstak and Enginads site search!


All use is subject to our TERMS OF SERVICE
SMOKSTAK® is a Registered Trade Mark - A Community of Antique Engine Enthusiasts
Copyright © 2000 - 2019 by Harry Matthews P.O. Box 5612 - Sarasota, FL 34277