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Thread: R75/6 Won't Start - Always Has

  1. #1
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    R75/6 Won't Start - Always Has

    Been in the MOA for almost 30 years and this is my first post on the MOA forums, although I read them daily.

    I have a 1975 R75/6 that I bought new in 1975. It's always worked flawlessly - always. Today I tried to start it and nothing. Last ridden exactly a week ago - started right up. Battery is fully charged and always stays on a Battery Tender. Today when I pressed the starter - nothing. Instrument lights - neutral, brake, and alternator all glowing brightly. Starter didn't even try to engage - nothing. All switches normal. Clutch in or out doesn't matter.

    Anyone got any ideas where I should start looking for a cause? Starter button? Starter? Corrosion somewhere?

    Thanks in advance for any help.

    Bill Edwards
    Boerne, TX

  2. #2
    Administrator 20774's Avatar
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    Welcome Bill! Glad you've come out of lurk mode!

    Usually you should look at the battery first. You might think it's good, but it might not be. Be sure there's no corrosion on the connections. Connect a known-good voltmeter across the battery terminals...what does it read when you hit the starter button? That's the best load test there is. If it drops to below 9v, dead battery. If it doesn't change at all when you hit the button, it's something else.

    The next thing you should think about is the starter relay under the tank, left side. It's a small black cube. Good chance that corrosion has set up on the terminals. Work the relay out of the socket and plug/unplug it several times...that should help cut through the corrosion. Better yet, find a good cleaning/lubing spray (dielectric)...probably can get it a RatShack.

    After that, it gets harder to troubleshoot. You have to work closer to the starter under the engine top cover and find out the voltages at the main connections to the starter.

    Try the simple stuff first.
    Kurt -- Forum Administrator ---> 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!

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    Kurt,

    Thanks for the quick reply. As a follow up to my original post, I left the battery off of the Tender overnight figuring I'd try to eliminate a variable. So, I went out this morning to check the battery voltage (12.97 static) and then hit the starter to load check it, and.................................she started right up, just like she always has. Spun quickly and fired right up. I'll get the tank off this morning and check the relay anyway, and probably pull the cover over the starter itself to check connections.

    Again thanks for the reply. I'll post if I find anything concerning the relay or the starter connections.

    Bill Edwards
    Boerne, TX

  4. #4
    ABC,AMA(LIFE),MOA,RA,IBMW MANICMECHANIC's Avatar
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    Also check your push=button switch for connectivity. On my /6, sometimes it's like having to hold your tongue right when starting. Got to push the button just right.
    F.O.G.Rider, Rounder #6,
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    Once, I had to replace the "hot" cable that goes from the battery to the starter. It must have had a fracture in it somewhere. My symptoms were the same as yours - lights, gauges, etc. were on, but not enough juice going to the starter. That was about 20 years ago on my /6.

  6. #6
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    Maybe also the kill switch starting to go bad.
    Howard Edwards

    2014 Road King; 1975 R75/6

  7. #7
    Minnesota Nice! braddog's Avatar
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    I had a similar problem with my RS. The first thing I did was short the relay to engage the starter, and the starter engaged just fine. I had already replaced the existing relay with a new one, and had made sure all connections were clean.

    Next, looked at the red wires that basically provided the juice to the relay block. One was a jumper between the starter and horn relay. Not sure if the /6 is similar or not. Some of these were kind of corroded, somewhat rotten, so they were replaced with new wires and new connectors. Still didn't fix the problem.

    Then traced it back to the fact that the switch didn't seem to be working. This gave me a "Huh?" All switchgear was new like 2 years ago. Turns out the switchgear was fine, but the wire FROM the switch had become stretched when the handlebars had been adjusted downward. This caused intermittent connectivity, and eventually, NO connectivity.

    As you can see, this wasn't exactly textbook, logical troubleshooting. Some assumptions were made that shouldn't have been, but in the end, it was figured out.
    -----------------------------------------
    Brad D. - Member #105766
    '77 R100RS - Black Beauty (big pipe, baby!)
    '94 R1100RS - Sylvia

  8. #8
    Motorcyclist patiodadio's Avatar
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    Ok, after reading these post, not sure if its what I have.... My 1988 R100RT has always started great but while riding this weekend with the bike being hot, it would not start. Turn the key on and everything lights up fine but when you hit the button, nothing, no sound no click, nothing. Pushed it to bump start and it fires right up. Got back home, let it set over night, went out and it started right up this morning. What's going on ? Relay maybe ? Anyone have this happen ?



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    Enjoying this thread

    fwiw
    My 77 R75/7 did exactly that, when hot not restart. Replaced the starter relay no problems since. If you replace the SR make sure you
    clean the couplers inside SR socket too.

    A clue that it could be the SR, listen for a soft / faint single click when you hit the starter. Its gotta be real quiet in order to hear it.

  10. #10
    Motorcyclist patiodadio's Avatar
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    Quote Originally Posted by FUHGAWEE View Post
    Enjoying this thread

    fwiw
    My 77 R75/7 did exactly that, when hot not restart. Replaced the starter relay no problems since. If you replace the SR make sure you
    clean the couplers inside SR socket too.

    A clue that it could be the SR, listen for a soft / faint single click when you hit the starter. Its gotta be real quiet in order to hear it.
    Thanks !



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    The early bird might get the worm, but the second mouse gets the cheese.

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