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Thread: r80 ignition problems

  1. #1
    Loading the Bike
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    r80 ignition problems

    Hi, I'm new to this forum thing, but want to ask if someone knows about r80 ignitions. Runs fine on startup, but after @ 15 minutes I Think I notice it getting a little weak. After that it starts cutting out-- sometimes at 35 mph it cuts out but restarts by itself. Mostly it just DIES: will often restart immediately with starter motor. Last time it would not restart for about 45 minutes. After I pushed it up a long hill, heading for home it finally caught and I remembered just why my first few motorized vehicles were so exciting----every foot of progress was a marvel of NOT WALKING

  2. #2
    Liaison 20774's Avatar
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    Could you tell us what year R80 you're talking about? If it were a '81-on bike, the first thing that comes to mind for me is the heat sink paste needs to be renewed on the ignition module. Without proper heat transfer, the module heats up and quits working. It could be issues associated with the carb or the fact that your tank is not venting, thus prevent fuel from gravity flowing into the carbs.

    Edit...I see by your profile that the bike is a 1985.
    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
    Registered User widebmw's Avatar
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    It sounds like something heating up.
    There are only a couple of things that do that.
    Ignition control unit, (the little black box under the seat ) is the first one I would look at because it is quick to replace.
    The best way is if you can find another airhead to swap parts with.
    I think someone on this forum could help, it would olny take a couple of hours to swap parts and test ride.

  4. #4
    Luddite Looney wecm31's Avatar
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    I 'll jump on the band wagon and suspect the ignition module as well. It is reportedly a classic intermittent problem, cuts out when hot and runs again after it cools down a bit. Start with replacing the heat sink paste (Radio Shack has a small tube of white goo for a few bucks, last you years). I remain wary of black box items that I can't see the fault or test road side. I ordered an aftermarket module (one of the rare non-BMW parts I use) from http://www.rockypointcycle.com/

    At only ~$25, it is on the bike now and the original I carry as a spare.

    I do recall hearing of a test method for the module, others please correct me if I get this wrong. With a plug pulled and grounded to the engine, if the ignition is on and you cycle the kill switch, you will see one spark. Does that make sense? This would only help if the module was dead. If its just overheating, you would have to catch it hot to see no spark, would be fine cold.
    Gerald P
    The last thing I want to be is just like everyone else...
    1985 R80RT
    1969 Sport Fury Convertible

  5. #5
    Registered User widebmw's Avatar
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    Once it has gone so far as to start cutting out the heat damage is done, new paste will not help.

    I had a similar problem last year and it was the ignition sensor and I got a new one from Motorrad Elektrik, it works great.

    http://www.motoelekt.com/ignition.htm

    You still need the heat sink paste when you install it. Just a thin film.

    Still it could be something else if you cold swap parts with a running late model airhead you would be sure.

  6. #6
    Registered User lkchris's Avatar
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    Sounds like carburetion to me.

    And, on the newer bikes this includes whether fuel gets to the carbs from the tank via all the new systems.
    Kent Christensen
    21482
    '12 R1200RT, '02 R1100S, '84 R80G/S

  7. #7
    Stage Crew beemerPhil's Avatar
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    +1 Kurt.


    The heat transfer compound dissipates over time. If yours hasn't been replaced in a few years, this would be a knee-jerk.

    So long as the ignition module hasn't been destroyed by over-heating, a dose of compound should resolve the problem entirely.

    If the bike still runs cold, the module apparently hasn't been damaged; remove the module, separate it from the heat sink. Clean the mating surfaces of both parts, and apply a THIN coat of compound (cheap, from Radio Shack- silicone heat transfer compound) to both surfaces.

    You want just enough to ensure good contact between the surfaces; trying to squeeze out excess compound by tightening the mounting screws against it risks fracturing the control board. Tighten the screws gently- let the compound settle between the parts. Clean up the stuff that squeezes out with a paper towel; it doesn't wash out very well.

    Put things back where they belong, with a little vaseline on the terminals, and you should be good to go.



    YMMV

    Had this happen on my '84 R100RS out in Illinois a few years back. It would quit, I'd pull over, and in 10-15 minutes it would start right up and run fine for 5 or 10 miles, then repeat.

    New goo, and it hasn't missed a beat since.....

    FWIW, the module isn't very expensive- I got one on ebay for $15 or $20, and stuck it in the toolkit just in case. Carried it around for a couple years, til I wanted the space back for something else, and tossed in my parts drawer back home.
    Phil Keppelman #20331
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    The shortest distance between two points.............ain't how I got here......

  8. #8
    Registered User PHMARVIN's Avatar
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    Hi, Mikeydog47,
    It might be the module everyone is giving you advice to fix. It could also be a clogged vent. When it happens, unscrew your gas cap. Do you hear a "whoosh"? If so, it's probably a tank venting problem. The earlier caps ('77-84, I believe) are vented and later ones are non-vented. With the later bikes, there are hoses, solenoids, etc. to keep any molecule of fuel from escaping into the atmosphere. If you have a later bike, for example, and have removed all that crap but still have the original cap, your tank might not be venting, thus fuel won't flow. I had the opposite problem with an '81 R100RT I bought. The P.O. had replaced the cap - with the wrong one! When I finally figured out the problem and got the correct cap, problem solved. Good Luck!
    Ride Safe,
    Phil Marvin - El Paso, TX
    '94 K75A/3
    '95 K75RTP

  9. #9
    Luddite Looney wecm31's Avatar
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    Reading mikeydog's profile, he has a 85 R80, as do I. Phil, you do have me pondering just how the cap vents, through the key slot?? But I don't have any extra fuel contraptions at all; two lines to the carbs and the overflow. No wires or solenoids. I think that starts 86/87?? I'm still leaning to ignition....
    Last edited by wecm31; 01-24-2010 at 03:43 AM. Reason: comment from crossing over threads removed
    Gerald P
    The last thing I want to be is just like everyone else...
    1985 R80RT
    1969 Sport Fury Convertible

  10. #10
    Loading the Bike
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    r80 igntion problems

    Wow thanks everyone , I didn't expect a reply this soon. I'll head to Radio Shack this weekend. By the way, when it cuts out while moving, it backfires when it resumes ( real attentiongetter going by a police car), so I think it's getting fuel, but whaddoiknow? thanks again all

  11. #11
    Registered User mneblett's Avatar
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    When did the crappy (and cracking) grey twin-tower coils start being used? My '88 had one, but I don't know whether the '85's did.

    These are well-known intermittant ignition killers, *especially* if they see any moisture.

  12. #12
    mymindsok
    Guest
    Uhmmm...

    I'm not going to argue with you guys but there may well be another culprit in this mystery.

    My 83 RS was acting the same way last summer. It would run great and then, sometimes at 85mph in heavy traffic, the bike would die. After it sat for five, ten or 15 minutes, it would carry on for a spell and then die again.

    I swapped in a new ICM but the real problem was the Hall effect sensor in the bean can. After swapping in the new can ($500.00!) the bike has run flawlessly for the last 8000 miles.

  13. #13
    Registered User beemerguru's Avatar
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    You've been riding in the rain...take a look for cracks in the coil. Also, an automatic restart with a backfire is also a symptom of the ignition canister going bad. Also check the spark plug wires especially if you're still running the metal cap originals...they short out over time...like in the rain.

    Or come on over to Foster City and we can have some fun finding a solution .
    Greg Hutchinson
    R80G/S (4) 633CSi with 450K mile
    '68 R60/2 '88 K100RS Special Edition
    http://gregsgssite.shutterfly.com/

  14. #14
    Bill Burke
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    Here are some ideas for intermittent cutout:

    Renew the heat sink paste in your ignition module (others can help on that if you haven't done it before);

    and


    1. To test coils and ignition module: Pull a spark plug, insert it back into the plug wire cap, and ground it securely on the cylinder jug. Turn the ignition key to ON. Place the kill switch in the RUN position. Now, watch the plug while flipping the kill switch on and off. You should get a spark as the switch is turned off. If you DO get a spark, this indicates that both your coils and your ignition module are functional and you can focus on the ignition sensor.

    2. To test ignition sensor (bean can) under front cover: remove negative cable from battery, remove front cover to access bean can. Remove a spark plug and ground it to engine as in 1 above. Find the electrical wire that leads from the bean can upwards to connect with the main harness. Disconnect that connector by carefully removing a thin wire bail that holds the two halves of the connector together. Pull the plug apart. Using about a three inch length of thin wire, insert an end of the wire into the MIDDLE female hole of the three-hole connector that leads to the bike's harness (not the remaining half of the connector that's made up to the beancan). Connect negative ground to battery. Turn on ignition to bike. Place kill switch in Run position. Now, while the thin wire remains inserted in the middle female connector hole, strike the other end against the metal alternator cover as though you're striking a match. If, when you "strike the match" you also get a spark on the grounded spark plug, your hall effect sensor has failed.

    Rick Jones at motorrad electrik rebuilds them for about $175. New ones are about $500.
    Last edited by Bill Burke; 01-24-2010 at 02:38 PM.

  15. #15

    R80 86´Ignition modul, how much warming up?

    Hi! After the engine started in about 30 seconds, the aluminum radiator on the ignition modul is hot so that it burns in the finger. How much should it warm up? Is anything wrong? Ignition modul is new. Thanks!

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