Results 1 to 4 of 4

Thread: Coil Sparking on Start

  1. #1
    Registered User Manitou_Commando's Avatar
    Join Date
    Mar 2008
    Manitou Springs, CO

    Coil Sparking on Start

    While putting is a starter on an '88 R100RS, I saw that the coil was throwing off a spark, only while I press the starter button. When it's idling, it doesn't spark. I removed the

    Enduralast twin tower, 0.07Ohm coil from the bike, cleaned it and the three connections to the harness. Running my thumbnail of the surface, I neither saw of felt any cracks.

    Put it back together and it still sparks, but only while the starter button is depressed. No sparking while idling.

    New coil time or not? Thoughts?

    "It ain't what you don't know that gets you into trouble. It's what you know for sure that just ain't so." Mark Twain

  2. #2
    Registered User STEVENRANKIN's Avatar
    Join Date
    Dec 2006
    Spencerport, NY

    Spark plug lead?

    You don't say where the coil is sparking?

    Is it possible your spark plug lead has bit the dust? They don't last forever. A breakdown in insulation will cause the spark to jump to the nearest metal. It could just be a coincidence that it is noticeable when you have the starter button pushed.

    I used to poke around the spark plug wires with an insulated large screwdriver grounded to something, at night to find a bad spark plug lead.

    My sister's Isuzu PUP used to give the best light show! It ate spark plug leads every two years. St.

  3. #3
    Registered User lkchris's Avatar
    Join Date
    Mar 2003
    Albuquerque, NM
    Your coil gets 12V while the starter motor is running.

    After that, it runs on 6V.
    Kent Christensen
    '12 R1200RT, '02 R1100S, '84 R80G/S

  4. #4
    Registered User STEVENRANKIN's Avatar
    Join Date
    Dec 2006
    Spencerport, NY

    Snowbum's website

    This fellow, is one of the true experts on BMW motorcycles.

    Perhaps reading some of the information he has posted at

    Could solve the problem. St.

Similar Threads

  1. How to check for sparking on '88 K75C
    By rall275 in forum Flying Brick K-bikes
    Replies: 1
    Last Post: 07-18-2018, 09:40 PM
  2. Replies: 11
    Last Post: 06-09-2013, 02:13 AM
  3. Hard start - no start problem
    By droberts in forum Flying Brick K-bikes
    Replies: 8
    Last Post: 06-18-2009, 09:04 PM
  4. Wet coil
    By RandyB in forum Airheads
    Replies: 2
    Last Post: 12-30-2006, 04:32 PM
  5. To start or not start bike in the winter
    By terham in forum Oilheads
    Replies: 10
    Last Post: 12-11-2006, 11:33 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts