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Thread: Airhead cuts out

  1. #1
    Registered User arptra's Avatar
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    Airhead cuts out

    Hello all, My r100 with bean can cuts out every now and then, just for a second when it is cold or hot usually at speed except yesterday as I pulled off my street with motor cold it stopped, backfired and I had to restart it and it fired right up. I'm about to dive into it and was wondering if anyone had any ideas? Headed for control module first, I do not think there is any gel on it. Thanks
    Alan,
    Dallas Texas
    74 R90S, 81 R100CS, 95 R100GSPD, 12 R1200RT

  2. #2
    MOA,ABC,AMA,NEF,BREC,CCA brownie's Avatar
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    Cut out stuff

    Loose/worn plug wires? Cracked coil(s), lo volt issues to coil (s)? My $0.02
    Words to Ride by: Patience, Anticipate, Paranoia
    Shep Brown MOA 27510
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  3. #3
    Registered User arptra's Avatar
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    It loses all power for a second, something to do with ignition I'm sure, or kill switch.
    Alan,
    Dallas Texas
    74 R90S, 81 R100CS, 95 R100GSPD, 12 R1200RT

  4. #4
    Heat sink paste on the ignition control unit? Loose jumper wire between the coils? Loose battery ground?

  5. #5
    Registered User arptra's Avatar
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    Quote Originally Posted by khittner1 View Post
    Heat sink paste on the ignition control unit? Loose jumper wire between the coils? Loose battery ground?
    I read about heat sink but I thought that was when motor was hot
    Alan,
    Dallas Texas
    74 R90S, 81 R100CS, 95 R100GSPD, 12 R1200RT

  6. #6
    Registered User arptra's Avatar
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    This last time I think the dash lights also went out, I ordered new switch gear today, need them anyway.
    Alan,
    Dallas Texas
    74 R90S, 81 R100CS, 95 R100GSPD, 12 R1200RT

  7. #7
    ABC,AMA(LIFE),MOA,RA,IBMW MANICMECHANIC's Avatar
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    Ceck the connections to/around the starter relay. Also your ground connection to the transmission for snug.
    F.O.G.Rider, Rounder #6,
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  8. #8
    Mine did that and I traced it to the connections just under the front left side of the tank. I cleaned them all (relays, etc) and then made a "shield" out of an old milk gallon jug (plastic) and have never had the problem since. On mine, at one time there must have been a brake cylinder leak under tank and these connections are right near the brake cylinder.
    Last edited by SCBuckeye; 04-15-2017 at 06:33 PM.
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  9. #9
    Rally Rat 1074's Avatar
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    It sure would help if we knew what year this bike is. On that note, there is an Airhead Tech Day listed here on the forum. You might want to go there this weekend.
    Boxerbruce

  10. #10
    Registered User arptra's Avatar
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    Thanks guys, I will check those, 81 R100
    Alan,
    Dallas Texas
    74 R90S, 81 R100CS, 95 R100GSPD, 12 R1200RT

  11. #11
    Registered User lowndes's Avatar
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    Arptra,

    My brother had a very similar problem with his '79 R100RT for MONTHS. And he is an old MC mechanic from way back, still works for an antique MC racer part time doing engine rebuilds and restorations, so he "knows a thing or two" about bikes. Cold or hot, at least once every ride, it woud just die, riding down the road or still in the parking lot. Drove us nuts, me because I'd be behind him and it would die, he'd switch it OFF then ON again and it would be the biggest, loudest backfire you ever saw with yellow flames shooting out 10 feet. Scare the bejeebers out of me. It was most definitely a safety issue, too, loosing power when passing, etc. Most of the time it would restart immediately, sometimes it would take a minute or two, but always restarted.

    He replaced or swapped out everything, ignition switches, relays, handle bar controls, coils, wires, plugs, boots, even sections of the wiring harness. Turns out it was the neg battery cable that was corroded INSIDE the insulation from battery acid, and not visible from the outside. It was almost completely severed. Not sure exactly the electrical/mechanical problem resulted in these symptoms, but it did.

    He finally found it by process of elimination, installing temporary bypasses around the existing switches, relays, connectors, etc. Bad "grounds" are always a very difficult prob to sort out and the last thing we think about. He rebuilt the ground cable with new lugs and sealed the ends of the insulation with heat shrink and silicone about 6 weeks ago and problem solved.

    GOOD LUCK with this, and please LET US KNOW what you find when you do find it!!

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