Build thread blah blah blah R75/6 "Ernst"

Discussion in 'Airheads' started by melville, Jun 23, 2010.

  1. melville

    melville Long timer

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    No, it wasn't that at all. The passing beam takes its power from the red (always hot) wire that goes directly to the dip switch. It was getting no power from the relay. The light relay was doing everything it should EXCEPT power up terminal #87. Searching out a new light relay to check now.

    I may have issues with the dip switch, in that it does not hold high beam. I presume that there should be a detent to hold low or high, with passing beam available momentarily. The switch does not hold high beam, but springs back to low. I'm not too concerned yet, as my contract stipulates that I am to be a daytime only rider (and I'm OK with that).

    A wide shot mit the tank on to keep me inspired:

    [​IMG]
  2. The Killstar

    The Killstar Ted Simon Acolyte

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    That is going to be a beautiful bike. I've never noticed how those old boxers just hang on the frame. Looks kinda goofy with all the line and cables unattached.
  3. melville

    melville Long timer

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    More electrical voodoo! Trying to get my instrument/idiot lights to do their thing. When I made it run a couple years ago, some of them worked. When I put it back together, nothing lit up anymore. So after checking that I had the right signals coming to the plug, I went inside the instruments to see what was up. Most of the contacts inside were corroded where the copper film inside the flexible thingy met the contacts on the bulb holders. All the bulbs were still good after cleaning (sanding) the bulb holder contacts, but I could only get continuity on a few of the runs in the flexible thingy. Cleaning helped a couple, but hurt a couple more. The contact on the right has just had a few strokes of 600 grit paper, and it has lost the copper right where it makes contact with the bulb holder. I may try to solder some wires into it, but most likely I'm going to bend over and spend the $$ to get a new flexible thingy while they're still available.

    [​IMG]

    Speaking of soldering, is that the preferred method of getting the coil-end contact onto the HT spark plug leads? Any tips that you, my friends of the innerwebs, may have would be highly appreciated.
  4. DoktorT

    DoktorT BigBrowedNeandereer

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    I see no mention of SnoBum anywhere. Do yourself a favor and take the time to review in gross detail all relevant sections of this site>>>>>

    http://bmwmotorcycletech.info/techindex.htm

    Great project.
  5. melville

    melville Long timer

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    Gross Detail? Yowza!

    I've seen bits of Mr. Bum's site before but not the WHOLE THING AT ONCE.

    Oh my.
  6. e28rusty

    e28rusty Fool

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    Willamette valley, OR
    I can only dream of ever having a fraction of the patience you're putting into every nook and cranny on this bike. It really is looking awesome.
    I've been fighting with my idiot lights too, and I actually just gobbed some solder on the film where it was cracked, not graceful or pretty, but most of my lights work again :) I've learned to live without a "fern light" indicator.

    I can't wait to see the finished product.
  7. DoktorT

    DoktorT BigBrowedNeandereer

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    I got a T-2 too, a 72. It's now confirgured for tool shed duty to service the Airhead since I don't have a shop anymore. I do love simple, easy to maintain vehicles. Need to do ANYTHING, reconfigure the T-2. Need to blow out the cobwebs from your cranium, enter the RS.
  8. melville

    melville Long timer

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    Thanks! I can wait, but only enough to get it right.

    Yeah, I'm going to try to foodle with the existing flexicircuit thingy but I expect $$ will be leaving my pocket.
  9. melville

    melville Long timer

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    Yeah, not too much cranium cobweb blowing with my 50 hp '71 Kombi, which got all my mechanical attention today for a valve adjust and oil change.
  10. melville

    melville Long timer

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    Slayed a wee electrical dragon today--set the static timing, then cranked it and open-fired a plug to check for spark. Sparks were in the yellow-to-blue range, which is just fine with me given the state of the battery.

    I think I'm on the verge of a breakthrough as regards the headlight and its relay and the dipswitch. If it works, it will be the slickest thing I've ever coaxed out of this voodoo electricity. More to come this weekend.
  11. melville

    melville Long timer

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    Here it is the weekend. Y'all can get off the edges of your chairs, and stop holding your breath. I realized that in addition to having no power to the headlight that my dip switch was not functioning. It would not hold the high beam position. As a new left side switch runs nearly $200, and the other functions of the switch were just fine, I thought about how I could get high beam with just an intermittent signal from the switch. Then I drove the Kombi to go surfing before dawn one morning and I realized that VW had solved my problem 40 some years ago. Voila, a 1971 VW dimmer relay:

    [​IMG]

    And here's the schematic:

    [​IMG]

    So on this one, hot comes in at 56 and goes out to 56a or 56b. The choice of where it goes changes each time S is momentarily connected to ground. S (the switch circuit) gets its hot also from 56.

    Unfortunately, this relay came from my junk pile. It stuck once and shorted inside, taking out my last German voltage regulator. So I went to my VW FLAPS and scored a new one, just $30:

    [​IMG]

    The part number is slightly different, and it's intended for later WCVWs so there's a tiny functional difference. Also note that it's from Siemens/VDO, which makes me smile every time I think of VDO's aftermarket ad campaign from a while ago, "Help Spread VDO!" Clearly it's now, "Help Spread VDO with Siemens!" I'll be just a minute ROFL.































    And I'm back. The schematic is different:

    [​IMG]

    The switch circuit needs its own hot, coming in at 30. No big deal, as I can piggyback on the headlight hot, and it will function just like the earlier one.

    I try where I can, when I'm wiring stuff in, to match the DIN wire color. To make this one go, I needed yellow to go from 56a (low beam) to the junction board, and white to go from 56b (high beam) to the junction board. I also needed yellow/white to go from the main light relay to 56 on the dimmer relay. I didn't want to chase down a funky wire when I only needed a few inches, so I made my own yellow/white:

    [​IMG]

    It worked a trick:

    [​IMG]

    Wiring was like so: New yellow/white from 87 on the light relay to 56 on the dimmer relay. New yellow/white piggybacked from 87 on the light relay to 30 on the dimmer relay. New white from 56a on the dimmer to 56a on the junction board. New yellow from 56b on the dimmer relay to 56b on the junction board. I then connected the yellow/white from the dipswitch to S on the relay, and the white from the dipswitch to a spare ground on the circuit board. The yellow and red wires from the dipswitch are not used. They are taped up and put out of the way.

    The wiring works great--just a push up on the dipswitch takes it from low to high, and the indicator light should work as I have power to the appropriate pins in the instrument plug. The next push up takes it right back to low beam. I'm having some issues getting the headlight to mount to this crowded shell. I may have to relocate the dimmer relay under the tank, in the space made available by the recent starter and horn relay work.
  12. melville

    melville Long timer

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    So there's just no getting that new dimmer relay outta the way of the actual headlight:

    [​IMG]

    I'm going to have to build a wee bit o' harness and stick it under the tank.

    So after I found that out, I went to have fun with gorilla snot while the sun was out today. The stuff:

    [​IMG]

    Snot applied:

    [​IMG]

    Clamped:

    [​IMG]

    And all mounted up:

    [​IMG]
  13. melville

    melville Long timer

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    Those pesky electrons are going where I tell them, dammit! Got the dimmer relay relocated today.

    I wanted to use proper wiring harness style loom, and when I went to look for it Monday, I got shot down everywhere. The auto electric shops were all, "Yeah, I know what you want but I ain't got it." NAPA was the same. The HD shop is open on Mondays after Memorial Day, and they sold me 48 cents of shrink wrap tubing, saying "It oughta do it" when I described the application.

    Not completely happy with all that, I stopped by my local airhead guy's shop when he was open on Tuesday, and he was all "What size and how many feet?" He had the genuine stuff, and I felt much better about my prospects on this job. My local airhead guy is an inmate http://advrider.com/forums/member.php?u=8619 and an altogether nice guy. Here's his shop, if you are ever coming through here: http://www.northcoastcycle.com/aboutus.html

    The job--I started by making a bracket to hold the relay:

    [​IMG]

    Then I got the wires into the loom, marked DIN style so I knew which was which (I used 2 cents worth of the HD shrink tube on each end of the loom):

    [​IMG]

    Then got it all mounted and wired up:

    [​IMG]

    Ta Da! The headlight now fits, and has high and low beam at the touch of a button:

    [​IMG]

    And a couple wide shots, one with the tank on to make sure everything fits:

    [​IMG]

    [​IMG]

    If I'm up early enough, I'll check the aim of the headlight.
  14. melville

    melville Long timer

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    Fun mit metal today! Stock, my bike had a remote choke lever, which is actually on the motor, just behind the rider's left knee. It pulls a coupla cables which terminate at a pinch bolt on each carburetor, like this one:

    [​IMG]

    Now a pinch bolt is something quite familiar to me from my past life as a bicycle mechanic. As the cables needed replacement anyway, I wondered about how I might make the choke controls special or distinctive. I remember one guy on the old Boxerworks forum, probably Chuey, had made some out of old bicycle spokes. I have plenty of those! Here's 32 of them, only 20,000 miles:

    [​IMG]

    Now the first battle is to make a handle, one that I can operate mit moto gloves on:

    [​IMG]

    [​IMG]

    Then, to make it lollipop shaped:

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    Now it was time to make the loop solid. I tried some of the limited hot metal methods available to me, and none of them would take:

    [​IMG]

    So I ended up getting some 1/8 SS .028 wall tube and making crimps out of it, reinforced with mucho JB Weld:

    [​IMG]

    Drawing it down:

    [​IMG]

    And all done:

    [​IMG]

    And mounted, with moto glove test:

    [​IMG]

    Now the more observant of you might notice that the carb in these pictures is somewhat crusty. You might be asking yourself, "How could melville stand to have such crustiness in his life?" Well, I'll tell you--it disturbs me very much, but the first thing I did on this bike was rebuild the carbs from a box of loose parts, before I started the bling-a-thon. Looking at them now, I could spend the whole summer getting them up to my standard, or









    I could just bling the tops and bowls for now, and come back for the bodies the next time I rebuild them. Here's the quickie result:

    [​IMG]

    There's a lot of casting flash, and the deeper question of whether or not "BING" stays on the tops after the polish goes final. But that's for another day.
  15. Mr. Vintage

    Mr. Vintage Family Dude

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    Looking good!
  16. LasseNC

    LasseNC XSessive!

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    I love the level of detail in your writing, and, well the pics are nice too :)
  17. melville

    melville Long timer

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    Yeah, just avoiding other work by fiddling about polishing the carbs. I've done one cap and one bowl, and I think I'll stop here and pick up the shine project the next time I have the carbs apart for actual work. The left one is, as yet, unpolished and I think I'll leave it that way--one can see only one carb at a time, no?

    No-name carb top:

    [​IMG]

    A side view:

    [​IMG]

    And the view we'll all see when the bike goes down:

    [​IMG]

    Tomorrow it's back to dicking about with electricity, hoping to make the dash lights function.
  18. fishkens

    fishkens Long timer

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    You have a special touch and level of patience.
  19. bpeckm

    bpeckm Grin!

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    Bada-Bing!




    Good looking work, electrical and carbical....:wink:

    :D
  20. melville

    melville Long timer

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    Yeah, I didn't dick about with electricity until today. Mrs. melville has had me clearing brush and crap and making dump runs mit the Kombi in preparation for framing a deck on the east side of the house. Finally, back to our MC drama.

    So the dash lights were not functioning. This thing was the difficulty:

    [​IMG]

    It holds the various lights in place in the instrument pod, running power from the pins through some copper foil to flexible tangs which engage the bulb holders. I pulled the bulb holders and cleaned the contacts, but it didn't help. I then checked continuity from the pins to the tangs and found a few that weren't on speaking terms. I was prepared to buy a new flexible circuit board, but figured I'd try a little fix first. e28rusty mentioned gobbing on some solder to improve continuity, and I gave gobbing a go, first securing the unit to a board:

    [​IMG]

    Then gobbing some of the pins that weren't connected:

    [​IMG]

    [​IMG]

    This brought the hot back to the top four lights and the ground back to the high beam, turn signals, and instrument lights. I did not try to fix the ground side of the brake fluid level light, as it was in a tight space with a high probability of shorting out several other functions if I were to goof up.

    I put the pod back together, plugged it in, and turned the ignition on:

    [​IMG]

    I've got the neutral light and the OP light working, but the gen light was dark. Like on an alternator equipped VW, that light is a necessary part of the charging system, so I took the pod off and apart and looked for the trouble, as I had good continuity and a working bulb when I tested the stuff off the bike. I pulled the bulb holder and found these inside the gen light space:

    [​IMG]

    Those are bits of copper that fell off the tangs that meet the bulb holder, leaving them plastic and non-conducting. In a McGyver moment, I tried some wee bits of alu foil tucked in between the plastic and copper foil of the flexible circuit, and bent down to function as the copper tangs did before. And success!

    [​IMG]

    Pod now mounted up:

    [​IMG]

    I have the lights you see functioning, plus the instrument illumination. High beam indicator, turn signal indicator, and brake fluid level are not working, but I think I can live with that.