R90 s

Discussion in 'Airheads' started by walkingbear, Nov 23, 2012.

  1. walkingbear

    walkingbear Lets Play Chicken!

    Joined:
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    Scottsdale AZ..
    Just brought home the R90S from an inmate here.
    Was running before .. but we tried to fire her up this
    morning before loading it up in the van.

    Had the dash lights go on. Figure it was a weak battery.

    Got her home .. put it on a charger. NO LIGHTS at all.. just like when when tried to fire her before. Electrical switch in headlight is two position off or on.
    The emergency switch on the on position. ( could this be bad)

    Battery shows it has some juice in the battery.

    CLUES
    #1
  2. disston

    disston ShadeTreeExpert

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    A load test will tell you if the battery is good but as a general rule it should read 12.5 volts or more to start a vehicle.

    The R90S bikes are three years. Those years have differences between them every year. What year is yours?
    #2
  3. walkingbear

    walkingbear Lets Play Chicken!

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    Mine is a 75 R90S
    #3
  4. _cy_

    _cy_ Long timer

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    fuses are located in headlight bucket .. not necessary to remove fairing to get at.... carefully unscrew large band that holds headlight in place. carefully remove bulb assembly.

    you will find fuses inside ...

    to check out battery ... assuming it's a lead/acid.. charge to full preferably not with a trickle charger, which could take 2+ days to fully charge.

    then measure resting voltage of battery with a known to be accurate meter. 12.85v resting indicates a fully charged condition.

    to achieve resting battery state ... allow battery to sit overnight...or if you don't have time to wait... place a substantial load on battery for short durations. like honking horn a few times. this will scrub off any surface charge to allow a reasonably accurate volts reading.

    after you get R90S back running again... volt reading taken directly at battery should be 13.8-14.2 range with engine at mid range.

    wiring diagrams, etc are buried somewhere in my bringing R90S back to life thread. link in sig...
    #4
  5. walkingbear

    walkingbear Lets Play Chicken!

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    Ok, fully charged the battery. Meter to the inside headlight. Both fuses are good. Red wire has 12.65 volts . The switch I believe is bad. Key will only turn to parking light position and the lights on the dash sometimes go on. Anyone have one for sale?
    #5
  6. disston

    disston ShadeTreeExpert

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    Before you buy the very expensive ignition switch check the plug to the rear of the instrument pod. This large rubber plug is held in place by a small screw. It is not often a problem but the contacts when they get to the age of our bikes have become dirty for one thing and they have also lost some of their grip. the female part you will see is the rubber plug and the male part is the back of the instrument pod. Clean all of this. Look for any loose pins or holes in the plug that look enlarged. Sometimes they need a little adjusting. It's kinda hard to put contact grease on each pin but if you do just a tiny bit now and again you may avoid making a mess.

    Actually all the wires in the bike should have their contacts cleaned and dielectric grease applied as you are working around them.

    I'm not sure you have found the problem with the headlight switch. It seems you have jumped to this conclusion a bit. But tell me have you tested the switch to verify that it is the problem? I guess you have to unhook it and test for continuity. That sort of test I think.

    Edit; Or do I misunderstand you, is what you are saying is the key does not turn?
    #6
  7. _cy_

    _cy_ Long timer

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    there's a switch built into clutch lever assembly on R90S with early style controls. switch shorted out and kept my R90S from starting.

    by passed clutch lever switch .. no problems ever since. never bother to replace that switch.

    does your R90S have early or late style controls?

    [​IMG]
    #7
  8. _cy_

    _cy_ Long timer

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    one of my fav pictures ... R90S cockpit with 7,300 miles

    [​IMG]
    #8
  9. walkingbear

    walkingbear Lets Play Chicken!

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    MY TROUBLE SHOOTING:

    I have my 81 R100 next to the R90 and both headlights are off.
    The biggest difference are the fuses on the R90 are mound on one of the '
    headlight ears.

    Checked the battery connection= good and fully charged but can guaranty the life/value of the battery without having it fully tested

    Checked the connections to headlight fuses ( not blown and changed out to two new ones)

    Checked power to the switch ( 12.65 volts from red lead)

    Battery charger on battery while test switch. Light came on for with parking light. Switch will not switch to full open position. Pressed the start button and the whole system died again.

    Will test continuity in the morning.
    Will change out for a new battery in the morning.
    #9
  10. walkingbear

    walkingbear Lets Play Chicken!

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    I was searching Ebay for parts. There was this 75 R90S tank with 8 hours left to bid. I made a bid and a call to the seller. No only he has a pristine tank he also has the cowl, fairing , seat , headlight bucket plus harness and start switch. All in perfect paint except for one spot on the fairing.

    He also has mufflers and grab rails. Totally turn key project not. Not worry about painting any longer.

    [​IMG]

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    #10
  11. RecycledRS

    RecycledRS Along for the ride

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    Very nice score!
    #11
  12. _cy_

    _cy_ Long timer

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    fab score!!
    #12
  13. spo123

    spo123 Man About Town

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    I bet it is (was) EXPENSIVE!...:deal
    #13
  14. cas.vanderwoude

    cas.vanderwoude Adventurer

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    try to find CONDUCTIVE grease. Dielectric grease is NON-CONDUCTIVE. Conductive grease is best for promoting a good electrical contact (less is better). A 2 ounce jar of the stuff will last a lifetime. Dielectric grease is like petroleum jelly - best on the outside of the connection to prevent oxidation.
    #14