Jump to content

Unofficial Home of Old Simplicity & Allis-Chalmers Garden Tractors

Sign in to follow this  

checking the coil

Recommended Posts

is there a way to check the coil in a 12 hp briggs? the B12 ran about 10 minutes and died. there is no spark. the out of production book doesn't enlighten me and a search thru the club archives found no matches for 'check coil'. i am heading out to get a condensor but i wonder if there is a way to hook a meter to the wire from the coil lead that goes to the points to see that the coil itself is working. would like to know what i have to pull the engine for as opposed to doing an exploratory

Share this post

Link to post
Share on other sites
Check ignition: Remove the spark plug and check for proper gap. Test for spark at the end of the secondary wire with a spark tester. If no spark, check for: 1. Incorrect armature air gap 2. Incorrect breaker point gap (should be 0.020" when points are open) 3. Dirty or oily points 4. Dirty or oily condenser hold down clip. A small amount of dirt, oil, or corrosion will keep the condenser from adequate grounding. 5. Wire extending through the condenser and shorting out 6. Shorted primary circuit wire. Trace the primary wire from the coil to the condenser or ignition module. There may be a break in the insulation. 7. Continuity of the primary wire. Sometimes the wire looks good but it is broken inside the insulation. Check for continuity with an ohm meter. 8. Shorted grounding or kill switch wire 9. Bad condenser 10. Bad coil (1 in 50 coils is bad) 11. Bad spark plug 12. Closed kill switch 13. Bad electronic ignition module Also check for missing or sheared flywheel key. The engine could still have spark but not at the correct time. http://iaa.umd.edu/walls/INAG207/Ignition/Ignitionsteps.html

Share this post

Link to post
Share on other sites
changed the condensor, then regapped the points-shoulda done that first!- and bingo, got spark. but what i wanted to know was; if i put a multimeter to the wire from the coil to the condensor/points, what should i look for in a normally functioning coil? at the plug wire, i would just look for a spark to the engine block(wife says to just hold onto the wire and crank 'er over! done that before but never intentionally) just seems like there should be some kind of simple test that will tell the condition of the coil

Share this post

Link to post
Share on other sites
This topic is now closed to further replies.
Sign in to follow this  

  • Who's Online (See full list)

    • PhanDad
    • Bill725
    • BLT
    • Big Roy
    • rokon2813
    • bowhunt4life
    • GregB
  • Today's Birthdays

    No users celebrating today
  • Recent Status Updates

    • Paul M.Murphy

      Paul M.Murphy

      Hello glad I got on this site. I hope to upload a couple of photos of my Simplicity Broadmoor 
      Model 707 Tractor. I have replaced all the belts on it and installed a new ignition switch.
      Have a mower deck which was in poor shape , repaced a couple of bushings and welded the
      deck where there was some holes. The tractor and mower deck came from a friend and the 
      mower deck metal was getting pretty thin. Some new metal was put in it and we also undercoated the underside of the deck. This was done by my friend Greg Toulman.
      I have not put the mower deck on the tractor yet, waiting for Greg to come home and give me a hand. Can you please tell me if there is a manual for the mower deck and where I could get one.
      I would also like to get some moon wheel discs as well.
      I will try and down load some photos of the tractor when my wife shows me how to. 
      I really love driving this tractor and also how well it is made compare today's tractors, especially the flexible rear end and the rollers.
      Tell the next time 
      · 8 replies
    • jbrooks

      jbrooks  »  Talntedmrgreen

      folowing  this from a link at the downloads.  I just rescued an AC 920 with the lambodini diesel. I can' t download  yet .  Where did you find the PDF copy you posted. . I would like to figure out how to adjust the injection pump. 
      I assume it's a bosche, correct
      · 0 replies
  • Adverts