Jump to content

Nominations for Tractor of the Month
Garden Tractors and Parts on eBay



Photo
- - - - -

Convert A Model B Briggs to 12 V Coil Ignition


  • Please log in to reply
10 replies to this topic

#1 chieffan ONLINE  

chieffan
  • Senior Member
  • Contributor
  • Member No: 62695
  • 6,147 Thanks
  • 4,491 posts
  • Location: SW Iowa

Posted September 19, 2015 - 09:52 AM

This engine is in a Gardener . That is why I posted in this category. For those who have been so helpful with my other post on this Model B not wanting to start, looking at another possibility. Might have found a new coil for $130. (Only paid $150 for the tractor with a plow and 2 new tires.) The conclusion has been reached that the coil is to week to fire the plug consistently under pressure. I have converted it over to electronic ignition. WILL THIS IDEA WORK?? The coil will operate the ignition module OK. The original points and condenser are no longer used. Can I use the original coil to trigger the ignition module which tells when the plug is to fire.  Connect a wire from the original coil and module connection, to the output side of the 12V coil and capacitor. Power the coil from a 12 V battery. Run the plug wire from the coil to the plug. OR: Run the ground wire from the module to the 12V coil and condenser? Which one of these ways will work, if either of them will work? I have all the components on hand. This machine is not used enough to justify the $130 coil. Only used to cultivate the taller row crops and to plow out sweet potatoes (which it didn't do as it would not start.)


Edited by chieffan, September 19, 2015 - 09:56 AM.

  • holdenboy1960 said thank you

#2 classic ONLINE  

classic
  • Senior Member
  • Member No: 52970
  • 3,449 Thanks
  • 1,603 posts
  • Location: New York

Posted September 19, 2015 - 10:30 AM

I have a Briggs model ZZ on a WW2 generator that operates off of a car coil. I bought the generator that way. The plug wire goes from the car coil to the spark plug, but I never pulled it apart to see how it's wired. The B and ZZ have the same coils.
  • holdenboy1960 and chieffan have said thanks

#3 DougT ONLINE  

DougT

    Dog Approved

  • Super Moderator
  • Staff
  • -GTt Supporter-
  • Contributor
  • Member No: 584
  • 5,718 Thanks
  • 4,276 posts
  • Location: north central Ohio

Posted September 19, 2015 - 11:53 AM

You will need to go back to the points and condenser to make it work. Just hook 12v through a toggle switch to the positive side of the coil and run the negative side of the coil through the points. Leave the original coil wire unhooked. Hook the battery ground to the frame. You will either need a coil with an internal resistor or run an external ballast resistor in the circuit.
  • Lauber1, holdenboy1960 and chieffan have said thanks

#4 chieffan ONLINE  

chieffan
  • Senior Member
  • Contributor
  • Member No: 62695
  • 6,147 Thanks
  • 4,491 posts
  • Location: SW Iowa

Posted September 19, 2015 - 01:29 PM

You will need to go back to the points and condenser to make it work. Just hook 12v through a toggle switch to the positive side of the coil and run the negative side of the coil through the points. Leave the original coil wire unhooked. Hook the battery ground to the frame. You will either need a coil with an internal resistor or run an external ballast resistor in the circuit.

Using the original points and condenser is not a problem as the points have not been changed.  What is the resistor for and where does it go?  Between the coil and the points?  What size resistor? 

 

Sound easy enough to make work and a lot cheaper than replacing the coil.  Thanks much for that information.


  • holdenboy1960 said thank you

#5 Bruce Dorsi ONLINE  

Bruce Dorsi

    Old, but not dead -- yet!

  • Senior Member
  • -GTt Supporter-
  • Contributor
  • Member No: 1525
  • 3,169 Thanks
  • 2,142 posts
  • Location: New Jersey

Posted September 19, 2015 - 01:59 PM

A resistance (not necessarily a resistor) is needed to limit the amount of current going through the coil & points.

 

Some "round-can" ignition coils are labeled as "no external resistor required."  ....These coils have additional windings in their primary circuit to achieve the necessary resistance.

 

Here is a Balkamp coil with internal resistance available thru NAPA stores, as well as other stores:

http://www.napaonlin...7080_0444703280

 

Other round-can coils may not be marked, or may be marked "external resistor required" or "no resistor".  ....A universal ballast resistor can be used in series between the battery and the coil's battery terminal. 

  

Here is the Balkamp coil without internal resistance: http://www.napaonlin...1016_0444703644

 

Here is an example of a universal ballast resistor: http://www.napaonlin...11SB_0196918261

 

These items are available through most auto parts stores, tractor supply stores, or equipment dealers.  ...They can be found under many brand names, with varying quality.  .... Balkamp , Echlin, & Standard are some trusted brands.

 

Edit:  I see you already have a coil.  .....Do you know which type it is?


Edited by Bruce Dorsi, September 19, 2015 - 02:02 PM.

  • holdenboy1960 and chieffan have said thanks

#6 chieffan ONLINE  

chieffan
  • Senior Member
  • Contributor
  • Member No: 62695
  • 6,147 Thanks
  • 4,491 posts
  • Location: SW Iowa

Posted September 19, 2015 - 02:43 PM

A resistance (not necessarily a resistor) is needed to limit the amount of current going through the coil & points.

 

Some "round-can" ignition coils are labeled as "no external resistor required."  ....These coils have additional windings in their primary circuit to achieve the necessary resistance.

 

Here is a Balkamp coil with internal resistance available thru NAPA stores, as well as other stores:

http://www.napaonlin...7080_0444703280

 

Other round-can coils may not be marked, or may be marked "external resistor required" or "no resistor".  ....A universal ballast resistor can be used in series between the battery and the coil's battery terminal. 

  

Here is the Balkamp coil without internal resistance: http://www.napaonlin...1016_0444703644

 

Here is an example of a universal ballast resistor: http://www.napaonlin...11SB_0196918261

 

These items are available through most auto parts stores, tractor supply stores, or equipment dealers.  ...They can be found under many brand names, with varying quality.  .... Balkamp , Echlin, & Standard are some trusted brands.

 

Edit:  I see you already have a coil.  .....Do you know which type it is?

The coil is off a 8 hp Wisconsin single cylinder.  Have not looked it over close to see what is on it.  My guess is internal resistor but could be wrong on that.


  • holdenboy1960 said thank you

#7 Bruce Dorsi ONLINE  

Bruce Dorsi

    Old, but not dead -- yet!

  • Senior Member
  • -GTt Supporter-
  • Contributor
  • Member No: 1525
  • 3,169 Thanks
  • 2,142 posts
  • Location: New Jersey

Posted September 19, 2015 - 03:58 PM

That should work !


  • chieffan said thank you

#8 chieffan ONLINE  

chieffan
  • Senior Member
  • Contributor
  • Member No: 62695
  • 6,147 Thanks
  • 4,491 posts
  • Location: SW Iowa

Posted September 19, 2015 - 06:53 PM

Went and got the coil.  Printed on the side "TO BE USED WITH RESISTOR" .  So, guess I better pick up a ballast resistor.



#9 Bruce Dorsi ONLINE  

Bruce Dorsi

    Old, but not dead -- yet!

  • Senior Member
  • -GTt Supporter-
  • Contributor
  • Member No: 1525
  • 3,169 Thanks
  • 2,142 posts
  • Location: New Jersey

Posted September 19, 2015 - 07:40 PM

Are you sure that came from a Wisconsin and is a 12 volt coil ?

 

Some of the older Wisconsin-powered equipment had 6 volt systems.

 

I know for fact that the 12 volt coils used on Bolens tractors did not require external resistors or have a resistance wire feeding the coil.


  • chieffan said thank you

#10 chieffan ONLINE  

chieffan
  • Senior Member
  • Contributor
  • Member No: 62695
  • 6,147 Thanks
  • 4,491 posts
  • Location: SW Iowa

Posted September 19, 2015 - 08:50 PM

I removed it from an 8HP Wisconsin this evening.  Printed on the coil is 12 VOLT  and TO BE USED WITH RESISTOR.  The tractor it came off was a Bolens 850.  I got the hood, engine, blade for a Med frame and sleeve hitch and some other useless parts.  Have no clue what was done prior to my purchasing the unit.  PO did say that it had a 6 volt starter generator and it went bad and he could not find another 6 volt unit so parted the tractor out.  I got what he had left.  I have also heard that all Wisconsin engines were 12 volt.  This coil could have been replaced back when too.  Don't know.  Just going to go by what is printed on the coil.



#11 chieffan ONLINE  

chieffan
  • Senior Member
  • Contributor
  • Member No: 62695
  • 6,147 Thanks
  • 4,491 posts
  • Location: SW Iowa

Posted September 21, 2015 - 06:00 PM

Got the tractor running this morning.  Used a ballast resistor with the coil.  Worked out great and it started on the second pull.  Let it sit with the gas turned off for an hour or more.  Went to start it and 3rd pull with full choke and it was running.  Drove it about 200 yds. down to the machine shed and ran like a clock.  Success at last but it has been one heck of a battle to say the least.  Talk about a learning experience ! !  Price just went up.  Shoot me an offer I can't refuse.  Or let me know what you have to trade in the line of Medium frame attachments.   Deck, snow caster, tiller,  ?? ? ?


Edited by chieffan, September 21, 2015 - 07:12 PM.

  • Alc, Bruce Dorsi, holdenboy1960 and 1 other said thanks




Top