This site uses cookies to maintain login information on FarmallCub.Com. Click the X in the banner upper right corner to close this notice. For more information on our privacy policy, visit this link:
Privacy Policy

NEW REGISTERED MEMBERS: Be sure to check your SPAM/JUNK folders for the activation email.

spark at the coil wire,but not the plug wire

The Cub Club -- Questions and answers to all of your Cub related issues.
Forum rules
Notice: For sale and wanted posts are not allowed in this forum. Please use our free classifieds or one of our site sponsors for your tractor and parts needs.
1ruralmailman
10+ Years
10+ Years
Posts: 4
Joined: Sat Apr 17, 2010 8:50 pm
Zip Code: 13778

spark at the coil wire,but not the plug wire

Postby 1ruralmailman » Sun Jan 08, 2017 1:55 pm

so i have spark from a new coil going directly to the block,but it will not fire through a plug wire with the plug grounded on the block.what am i missing?i believe since it sparks from the coil wire the points and condenser are working,yes or no?not sure what to look at next.

SPONSOR AD

Sponsor



Sponsor
 

Eugene
Team Cub Mentor
Team Cub Mentor
Posts: 20336
Joined: Fri Jul 02, 2004 9:52 pm
Zip Code: 65051
Circle of Safety: Y
Location: Mo. Linn

Re: spark at the coil wire,but not the plug wire

Postby Eugene » Sun Jan 08, 2017 2:11 pm

Several possibilities, bad plug wires, faulty rotor or distributor cap.
I have an excuse. CRS.

bofahs
5+ Years
5+ Years
Posts: 112
Joined: Sat Nov 26, 2016 6:03 pm
Zip Code: 31522
Tractors Owned: 1965 IH Cub Lo-Boy

Re: spark at the coil wire,but not the plug wire

Postby bofahs » Sun Jan 08, 2017 2:20 pm

If the coil wire sparks at the block, you must be doing it by "brushing by" the grounded block to unload the coil. Typically, the high voltage discharges through the coil wire to center of the distributor cap, through the rotor contact and rotor to the poles and plug wires.

So, it sounds like you've got a cap or rotor problem. This is often a corrosion problem, and I'd check that first. Clean the springy contact point on the rotor, lightly scrub the brass contact end of the rotor - then look at the inside of the cap - particularly the inside contacts where the rotor brushes past to dump the voltage to the plug wires.

None of this is, like, "Grunt, grunt, scrub, scrub" a very light dusting with fine sandpaper or Scotchbrite will fix it, if that's the problem. Heck, I've cleaned 'em with a Q-Tip!

Clean the points, of course. "They" say don't use it, but a cheap, paper, emery board has never failed me in this.

Yes, condensors have failed, but, wow, that's a rare failure.

Now, if all of that doesn't fix it, get a tune-up kit that includes a distributor cap, rotor, points cover, points and condensor; get a set of plug wires, and spend a happy 45 minutes putting all of that in.

User avatar
Bigdog
Team Cub Mentor
Team Cub Mentor
Posts: 24144
Joined: Sun Feb 02, 2003 12:50 pm
Zip Code: 43113
Circle of Safety: Y
Location: OH, Circleville
Contact:

Re: spark at the coil wire,but not the plug wire

Postby Bigdog » Sun Jan 08, 2017 9:14 pm

If you're getting spark at the coil secondary the points and condenser are ok. It's either a cap, rotor or timing problem.
Bigdog
If you can't fix it with a hammer, you've got an electrical problem.

My wife says I don't listen to her. - - - - - - - - Or something like that!

Image

http://www.cubtug.com


Return to “Farmall Cub”

Who is online

Users browsing this forum: Dave Downs, inairam and 25 guests