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Daves79x
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VBMWMO #9030
Joined: 08/09/2015
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I'm helping a friend with a '75 R90/6. Been sitting for 25 years. Had a Vetter fairing we removed. As many of you know, the fairing wiring required some considerable mods to the factory wiring. I think I have most of it figured out and done. But, of course, a couple of questions: we had to get a replacement ignition switch and the back terminals are labeled 58/30/15 across and the diagonal is #56. I've got the gray and red wires nailed down as #58 and #30. But I think 2 greens go on the other two, but what ones? I have a double green that has a bare connector on one end, and a single green left. Of the three connectors left, I'm sure one goes to the 'board' green, one to the #15 and one to #56. Just don't know which one. I see photos of switches with the #15 and #56 reversed marked as well. Hope I have the correct configuration switch for '75! Any help appreciated!

Dave

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Dave

Daves79x
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Update

I think I have the switch wires sorted. Power to dash, clock. Found the headlight switch faulty, can be fixed I think, and that brake fluid had cooked the 4-way flasher and starter relay. Starter also bad, turned briefly with screwdriver method, then dead. Removed and jumped directly from battery - dead. So more electrical work ahead. Good news is the front brake is as new, $350 later and the carbs are rebuilt in excellent shape!

Dave

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Dave

Daves79x
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Follow-Up FWIW

I'll reply again to myself, just in case anyone is interested. So had the starter checked - is fine. Replaced the starter relay with the AR152 from NAPA. Wired as described elsewhere many times. Replaced the 4-way flasher relay with a NAPA item also. Checked all grounds, charged the battery, cleaned the left-hand bar switches (what a bitc$ to get back together), checked the fuses, reinstalled starter (after grinding down two 13 mm box wrenches to fit the tight clearance - jeesh!

Hooked up the battery, turned key on and viola! The dash lit up, lighting works (headlight not plugged in yet), 4-way flasher works, horn,clock and voltmeter work - wow! Now the real test - hit the starter button and it turns over great. So - much progress.

The turn signals don't light up or flash using the signal switch, but they all work fine with the 4-way flasher switch. Need to check the bar switch and flasher there.

Carbs completely rebuilt, installed with new cables - one Q - do the cables run through the rubber cable locators on the frame under the tank? There appear to be holes there for both cables, although the originals were not run there.

Tank cleaned out and Karcoma petcocks completely rebuilt.

Dave

Getting pretty close to firing up - maybe later this week.

Dave

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Dave

schrader7032
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VBMWMO #7032
San Antonio, TX
Joined: 10/27/2006
Posts: 6590
IIRC the dual carb cables run

IIRC the dual carb cables run through the holes in the large grommet on my /7.

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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

Daves79x
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Thanks!

Thanks Kurt!

Dave

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Dave

Daves79x
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Another Update

Spent another 8 hours yesterday sorting wiring and actually got the bike running. Sounds pretty good! But still fighting the headlight switch and the turn signal relay. I just need a spring washer to hold the headlight switch tight to the contacts (all the washers/spring/ball were missing from the headlight bar switch and I had to source them with whatever I could find).

Then the turn signals - ended up removing the 4-way flasher assembly completely as it uses a separate relay to provide power to the stock signal relay/flasher unit and it was just too confusing to try to troubleshoot all that wiring. Put the stock flasher relay wiring all back to stock and now just have the indicator light on and no signal lights at all. Removed the relay cover and cleaned all contacts. Manually closed the contacts with power to the relay and nothing - it is just dead. So next is to replace that with a modern 3-pole flasher unit.

Otherwise, everything else works. Time and humidity sure take their toll on these old electrical systems. This bike sat in an unheated garage for almost 30 years.

But, at least it runs now and sound pretty good.

Dave

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Dave

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