R100/7 killed Valeo then 3 DB Electric Starter Planetary Gear Tracks after 3 yrs storage

Discussion in 'Airheads' started by joewmpls, May 2, 2020.

  1. joewmpls

    joewmpls n00b

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    Hello Airhead friends. I have a '78 R100/7 that is displaying strange starter killing behavior after being a beautiful starter and runner for years. Something developed during a couple years storage that caused difficult starting and starter killing- specifically the starter motor runs but planetary gear track gets stripped. I verified this as of this posting only in the Valeo, but the sounds and symptoms have been the same on the DB Electric starters (nearly identical to Valeo's).

    I'll list out the bike customizations that might matter for discussion to bring everyone up to speed on the current state of the system.

    Motogadget M-Unit to control electrics with digital buttons on the handlebars.
    Enduralast Digital Ignition
    Dyna 2-in-1 Coil
    Previous owner put newer Bings on that have the black plastic plate. He said it was off a 90's airhead.
    Siebenrock head kit
    NGK spark caps (I forget the specs)

    As the Frankenstein custom sits, it was starting and running beautifully for a couple years. A lithium battery had been used. Although it was a major pain in my ass, I ruled that out by augmenting it's shitty starting ability with hooking a car battery directly to the starter positive while trying to start this thing. Can anyone tell me why I read that I should not start the car when doing a jump-start connection like this? I haven't had issue with doing so, but would like to avoid it if possible.

    I ran the carbs dry before putting the bike in storage. I believe my father thought he was doing me a favor and started the bike while he stored it for me over the two years. He can't remember. After two years and a few months I tried to start with fresh gas and a fresh battery. It would not start and needed jumping to continue my efforts. There was coughing and a couple backfires and finally the starter broke. I say broke because I have yet to disassemble to find the exact problem. I can tell you that the motor sounded healthy and strong after something went wrong with the spline gear engagement. This is the same thing that happened on the next THREE DB Electric starters that I put in the bike. The most recent snapped the nose casting off today. My local Lakeville MN vintage/classic airhead mechanic Dale was convinced that the carbs had varnish in the jets. I disassembled and cleaned them before this most recent starter died too. This was my first time performing a carb clean and rebuild. I replaced all the rubber rings on the jets and other bits that I encountered, as well as the bowl seal. I cleaned the choke assembly and blew carb cleaner spray through everything. I followed a solid Youtube video while doing so. I soaked the parts in carb cleaner spray overnight, being the carb noob I am. Everything looked quite clean though. Starting today with 93 octane after all the cleaning seemed much more hopeful than the previous attempts, but alas, this starter died too! What gives!? I find nothing in the interwebs about such problems. BTW, this was 2-5 second bursts of starting. Both pipes blew slow gray smoke. I pulled the plugs after this and they were covered in thick black soot. They were new the last time I tried to start and blew the last starter.

    Any ideas?
    Thanks in advance!
    #1
  2. bmwrench

    bmwrench Long timer Supporter

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    My SWAG is that the ignition is advanced dramatically. Since the advance on these is electronic, it may mean that the ICU has failed. Another possibility is that gasoline filled the cylinders and even partially filled the crankcase.

    Car alternators can put out tremendous amperage, even at idle, so this could damage the electronics, or in the case of a bad battery in the bike, an explosion.
    #2
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  3. joewmpls

    joewmpls n00b

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    Sorry, although I am mechanically apt, I am not an experienced moto or auto mechanic, therefor a dangerous noob. Please help me understand what says that the timing might be too advanced. Is this a known problem for the EME Enduralast Ignitions and ICU's? I've been wondering what is up with the engine at a macro level because it seems to be presenting great difficulty to the starter if the starter internals are failing. I will post some pics of the flywheel and stater planetary gear track for reference. The planetary gear track is shredded in the center of the splines. I opened to to find grease/spline mud.

    Thanks for the feedback about car alternators. I will avoid that now :)

    Since I posted this I took apart the "original" Valeo starter (very fresh looking and likely newer) and found that the planetary gear track was stripped. I assume this is also what happened to the nearly identical DB Electric starters, having same symptoms.

    Thanks for the feedback!

    IMG_8584.jpg IMG_0614.jpg
    #3
  4. bmwrench

    bmwrench Long timer Supporter

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    Excessive advance makes for great resistance in starting, as combustion begins long before TDC. In old mechanics' terms, the engine "bucks" the starter, or kicks it back. I've found that EI, especially in the case of aftermarket ignitions, can do bizarre things. About all I can suggest is the use of a timing light with the spark plugs removed and grounded.
    #4
  5. joewmpls

    joewmpls n00b

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    It actually does seem like the the engine is "bucking" the starter. The ignition seems out of alignment. My local old airhead mechanic thinks that the cylinders could have rust. He had me smell the oil for gas. I'm bringing it in to him tomorrow. I'll report back what the verdict is. I'll relay the thoughts about the EI.

    Thanks!
    #5
  6. joewmpls

    joewmpls n00b

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    I don't know why I forgot this large detail, especially after you gave your SWAG. As soon as the bike is turned on, the EME Enduralast Enduraspark ignition begins firing back and for both cylinders. I noticed this when I tried to start it a year ago, but for some reason it didn't click in my mind right away how wrong that was. Obviously spark should only come from a detected timed rotation. :doh
    So... I guess this means the EME Trigger unit / ICU is bad?
    #6
  7. bmwrench

    bmwrench Long timer Supporter

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    I'd check the pickup/Hall Sensor/Whatever they used for magnetic deposits, or in the case of their optical sensor, debris on the lens. After that, I'd suspect a failure.
    #7