1982 BMW R100RS with no spark - help need

Discussion in 'Airheads' started by bushyb, Apr 14, 2012.

  1. bushyb

    bushyb Adventurer

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    I bought a R100RS that was in storage for 9 years, It went in good and running. It only needed a good clean and some TLC etc. On receiving the bike I checked compression and spark which was all good before I striped, cleaned and soda blasted it and high pressure washed it. Now on reassembly I found that I had no spark, I then fiddled around with the wires and got spark again. I later rechecked the spark and then there was once again no spark???? Not good, fiddle, fiddle spark, leave it a while no spark. AGH!!!!

    Remove the front cover, top cover and found the 3 pin plug connector from the ignition trigger assembly was not connected properly. Connect and great spark. Put it all back together and good spark. Leave it a day and rechecked NO SPARK!!! F*#@ &! Hell WTFH.

    Now here today I have stripped everything again, remover top and front cover, rechecked the connections etc no spark. Checked in the manual it’s a battery and coil triggered ignition by transistorised electronic system using Hall-effected transmitter.

    Now here I must tell you that I am absolutely hopeless with anything electrical and also don’t know the names of most of the components. I am not trying to start the bike at this stage but am check to see that all is good before final assembly and fitting the fairing etc.
    I need help to do a step by step test and check, advise on what special tools. I do not have a multi meter tester and most properly won’t know where to set if for what. Very frustrating. Thank in advance.
    #1
  2. ritetwist

    ritetwist Been here awhile

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    Careful with that high pressure washer,it will put water where an all day ride in the rain will not get.
    Not always good for electrics.
    I will let the others give more pertinent advice to your problem.
    #2
  3. bushyb

    bushyb Adventurer

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    I know I am new here, so not sure of posting photos, but you are most welcome to see the original bike photos and how it has progressed http://www.i-bmw.com/showthread.php?t=38097

    I went and bought a multimeter, so hopeing there is some help out there. Cheers.
    #3
  4. bushyb

    bushyb Adventurer

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    Thanks ritetwist, believe it or not I got it sorted out for now. One of the connectors that bolt to the coil even though tight was making a poor connections and was a bit corroded, took them all off and sand papered them and wire brushed the thread. Thanks <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:eek:ffice:eek:ffice" /><o:p></o:p>
    #4
  5. Bobmws

    Bobmws Curmudgeon At Large

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    I suggest you do that with every electrical connection on the bike, especially now while you have it apart. A little dielectric grease on the fittings to keep moisture and corrosion away in the future would be good too.
    #5
  6. hardwaregrrl

    hardwaregrrl ignore list

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    Hey, you would be better off cleaning ALL electrical connections with a product like this:

    <a href="http://hardwaregrrl.smugmug.com/Other/misc/16038929_6qzPj6#!i=1581432314&k=SGD8W2v&lb=1&s=A" title="Photo & Video Sharing by SmugMug"><img src="http://hardwaregrrl.smugmug.com/Other/misc/i-SGD8W2v/0/L/41Y5lTaQJfLSL500AA300-L.jpg" title="Photo & Video Sharing by SmugMug" alt="Photo & Video Sharing by SmugMug"></a>

    Avaliable at any auto parts store. Disconnect and squirt male and female connectors, then reconect and disconnect a few times. Then get a tube of dielectric grease, and put a bit on the connections. If you sandpaper the connectors, you could promote more corrosion.
    #6
  7. bmwloco

    bmwloco Long timer

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    Ditto Hardwaregrrl Obiwan knowledge from the earliest of boxer days.

    Uh huh.
    #7
  8. bushyb

    bushyb Adventurer

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    Thanks for all the advices, I will certinly lube the connectors.
    #8
  9. squish

    squish Out of the office.

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    Be super carefull with the CRC stuff around painted surfaces and plastics, especially ABS as some formulas like to soften the surface up real good.

    Hardwaregrrl brings up a really good point, you have to strike a balance between removing too much plating, and removing the corrosion.

    I've had good luck over the years using really fine wet or dry paper, wet to clean connections, especally ones that are either not plated or are so bad that it's my only choice.

    But once you have removed the corrosion and plateing you need to use somethign to waterproof the connection.
    #9