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Thread: Stick coil issues...???

  1. #1

    Stick coil issues...???

    OK - I'm getting more & more familiar w/ the R bike ('04 R1150R Rockster) and it's issues... I think I may have narrowed the problem down to failed stick coils.... After adjusting valves, syncing TB, changing plugs. Here is what I got... Hard starting when cold, engine feels sluggish and seems to have a flat spot under hard accelleration from 4.5k - 6k rpm. I've done some reading and given the idea that the primary stick coils could be bad. Here are the symptoms I've got - with the engine running/idling warmed up - I disconnected each primary coil one at a time and noticed absolutely no difference in how the engine runs. Knowing there are secondary plugs firing - I disconnected them both, and with both primaries connected, the bike would not start and only spit/sputtered. Reconnected secondary plugs and bike starts and runs like before. This would lead me to belive both stick coils are failed - how likely is that??? Is there away to test the input signal/voltage to the coils to make sure they are in deed failed - what actually triggers them - I assume the computer via the hall effect. Is it safe to say the same input goes to the secondary coils? So if that coil works the other output should be OK...?? Any input/opinions would help on this - I'm trying to determine in fact that the stick coils are bad... Thanks!!
    Last edited by ND4SPD68; 05-15-2009 at 03:29 AM.

  2. #2
    On the Road
    Join Date
    Feb 2008
    Location
    ATL. GA ,
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    45
    I lost my right side coil @ 18k miles.
    but we just did the unplug the coils game till we found it.
    I would think that if both failed you could not start that bike!
    I'm not your awnser but I think its just one bad coil!
    Both bad I have never heard of!
    But i'm a rookie so ....
    One of the ole timmers will pipe in and tell you how to check'um!
    Good luck !
    bd
    Attached Images Attached Images

  3. #3
    Actually - as my luck would have it, I do believe both stick coils are bad. The bike will not start with the primaries connected and the secondary plugs disconnected... That is what has me a little concerned that it is something more - it seems odd to have lost both. However - a little more history on the bike - I've only owned the bike for 3 weeks, it has 30k on it and it seemed to run good when I got it. Maybe a bit buzzy - which I initially contributed to it being a bit out of sync... Now I'm thinking that one coil was gone when I bought it, and now that I messed w/ it by changing the plugs (who knows once you disturb something), I may have caused the other to fail...

  4. #4
    Registered User
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    If you disconnect the secondary plugs be sure to ground the plug wire. The energy stored in the coil has to go somewhere. If the normal route is gone, then it will leak somewhere, cables or internal to the coil, both of these you do not want to happen. Also, the voltage the driver transistor in the Monotonic sees higher voltage than normal, there "should" be protection on it.

    Rod

  5. #5
    I grounded the secondary plug wires using an old set of spark plugs and grounded them to the engine case... Hope that's the correct way..???

  6. #6
    Registered User
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    You did good!!!!!!

    The stick coils have a high failure rate. The engine will run on the lower plugs so you are not down when one fails. Say they have a 25% failure rate. Your odds of having one fail are not 50% because some will have 2 fail and others will have none. You just happen to be in the extra special double unlucky group. This kind of failure puts your bike out of emissions compliance. The emissions warranty is set by the government, I have got free out of warranty repairs on cars because of that. Maybe you can read your emissions warranty, it is worth a shot, maybe it is longer than the BMW warranty.

    Rod

  7. #7
    Good thought re: the emissions warranty... I just purchased this bike 3 weeks ago and it came w/ 0 paperwork/manuals, etc... I already ordered new coils since there is a high probability they are the problem here. Looking forward to replacing them and seeing what the bike feels like. I will post the results of the replacements - I've got fingers crossed....
    Last edited by ND4SPD68; 05-19-2009 at 01:40 AM.

  8. #8
    endsley
    Guest

    Stich coil vs. Ignition coil

    am I correct in my assumption that a "Stick" coil ids the same as an "Ignition" coil? And if so is the term "stick coil" applicable to the single spark R1150 gs as well. Thanks,

  9. #9
    Registered User
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    15 M. E. Tampa
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    stick coils

    Stick coils are only used on the R1150 with four plugs. Instead of having a coil up under the gas tank passing electricity to the primary spark plugs directly, the coil is actually part of the spark plug boot assembly. The spark plug boot has a connector sticking out of the top that the spark plug wire hooks up to.
    The secondary plugs under the cylinders still use ye olde method, i.e. a coil up under the gas tank, and the boot is just a boot.

  10. #10

    Stick Coil / Ignition Coil

    And they look like this ...

    My 2004 R1150GS dual-spark had a single coil fail, at 17k miles (I've gotta get out more).

    The symptoms were hard starting, poor idle, rough running, and engine stalls when starting out from a stop. Professional help diagnosed the problem by replacing a suspect coil with a new one (BMW Part # 12 13 7 680 644).

    The new versions have a gray ring around the cap, as shown in the photograph, to differentiate from the older all-black versions.

    I replaced both coils, one by the pro, the other by myself. Easy to do and worth every penny.
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  11. #11
    Registered User beemermyke's Avatar
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    Richmond Hill, Georgia
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    I'll throw in my two cent's worth and vote for the coils too. I replaced mine on my 04 R1150RS at around 36,000 miles. (I did both because I figured if only one was bad, the other was likely not very far behind, considering the mileage on the bike.) My symptoms were intermittent reluctance to start when the bike was cool, and it just felt sluggish, especially when whacking the throttle at high speeds. I know that BMW has a "new and improved" coil, and I assume that this coil is the standard replacement now. The new one is gray in color where the wire runs into the coil, vs. the stock black one you likely have now. I don't normally like to "troubleshoot with my wallet", but the coils cured my bike's ails.

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