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Thread: 1979 R100RT Intermittent Not Starting

  1. #1
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    Unhappy 1979 R100RT Intermittent Not Starting

    Intermittently the starter will not even click or crank. Instrument lights are all lite and flicker when starter button pushed but no sound or start. When it does crank over it is strong and starts right up. Will be checking for power at starter this weekend. Need troubleshooting suggestions.

  2. #2
    Liaison 20774's Avatar
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    Welcome to the forum! When you take the gas tank off, look for the starter relay along the left side of the upper frame. It's a black cube about one inch on a side. It has 3-4 male terminals that plug into the base. Pull the relay out and replug several times...this will help clean off corrosion on the terminals.

    Also, check your battery terminals as well as the ground at the back of the transmission. How old is the battery? I wouldn't rule out the battery getting flaky.
    Kurt -- Forum Liaison ---> Resources and Links Thread <---
    '78 R100/7 & '69 R69S & '52 R25/2
    mine-ineye-deatheah-pielayah-jooa-kalayus. oolah-minane-hay-meeriah-kal-oyus-algay-a-thaykin', buddy!

  3. #3
    #4869 DennisDarrow's Avatar
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    Surely not anything with the engine....Wiring is the culprit and it's either a loose nothing little wire under the tank in all of that spaghetti or my first inclination, a loose ground. Either way it's just a matter of cleaning up the terminals on the starter relay system and then starting at the battery to the starter, cleaning and tightening ALL the connections. ALL of this stuff is 30 years old. It needs cleaning, replacement, and tightening up. Do that and get back to us....

  4. #4
    could be INSIDE the starter relay. It CAN be taken apart (carefully so as not to damage those teeny little wires) cleaned out, inside contacts freshened up with wet-or-dry, use electrical cleaner spray to clean them up, and reassembled.
    "The difference between death and taxes is that death doesn't change every time congress meets." - Will Rogers

  5. #5

    Intermittent Starting

    Quote Originally Posted by 43819 View Post
    Intermittently the starter will not even click or crank. Instrument lights are all lite and flicker when starter button pushed but no sound or start. When it does crank over it is strong and starts right up. Will be checking for power at starter this weekend. Need troubleshooting suggestions.
    How good are you with a multimeter?

    If you have one, set for DC volts. Place the Red (+) lead on the little black wire that runs to the starter solenoid and the black wire to engine ground.

    That's the small tube that is part of the starter. It's role is to pull in when the starter button is pressed, shorting out the 12volts from the battery to the starter.

    If you turn the ignition on, press the starter button, you should see 12vdc. That confirms that the starter button is clean, the starter relay under the tank is good and the wiring up to that point.

    RG

  6. #6
    We had a similar problem with a 95R100RT. Sometimes it would go for many many months without a problem and then nothing when I hit the starter. The starter relay was the problem. It's a simple plug in on my bike. I assume it is very similar on the other models.

    Adirondack Bob

  7. #7
    Registered User lmo1131's Avatar
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    Right off the bat(tery).... how old is it? Have it load tested. Just "seeing" 12V isn't an indication of it's ability to crank over the engine.
    "It is what you discover, after you know it all, that counts." _ John Wooden
    Lew Morris
    1973 R75/5 - original owner
    1963 Dnepr

  8. #8
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    Cool Intermittent Starter repaired

    I located the relay and found corrosion on a few of the pins. Cleaned the sockets with contact cleaner and installed a new starter-relay for good measure. Took it out for a multi stop errand runs today and it ran great and never missed a start. Now I'm back to adding to my windshield bug collection. . Thanks for the great advice.

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