Results 1 to 9 of 9

Thread: 1992 K75RT headlight bulb

  1. #1
    Dale Rudolph
    Join Date
    May 2009
    Location
    Medford, Oregon
    Posts
    579

    1992 K75RT headlight bulb

    I need to replace the headlight bulb on my 1992 K-75RT. Looking at my Clymers, I found out that it is a H-4 -60/55watt bulb. Two other items....do not touch the lens of the bulb and no bodywork needs to be taken off.

    I can just barely get my hand on the light socket. While I can probably get the socket out of the headlight, it looks like it is a two-hander to hold the socket and insert the bulb into the socket.
    Even if you can get both hands into the socket area, getting the bulb inserted without touching the lens looks like it won't be easy.

    Has anyone got any tips on doing this job? Did you end up taking any of the bodywork off in order to get to the socket?

    Thanks for any information.

  2. #2
    Registered User
    Join Date
    Apr 2012
    Location
    Los Angeles, CA
    Posts
    341
    I have a disassembled '86 RT fairing here in my garage. Assuming yours is relatively similar, here's how it works. Since it's not on the bike I'm not sure how you'll reach in, but if you can get your fingers onto the bulb's plug you should be good to go. You might be able to get in by reaching up from the front fender area, or down around the cluster.

    There's no "socket" per se. There's a rubber boot stuck onto the back of the bulb+reflector assembly. The prongs from the back of the bulb protrude through the rubber boot, and the headlight plug attaches to the prongs and presses up against the boot.

    So: Reach in, and unplug the headlight wire. (The plug will only fit one way. The three prongs form an inverted "U.") Just let it hang. Next, pull the rubber boot off. Mine has a tab on the left and right sides to facilitate this.

    The bulb itself is held in by a small retaining ring. You'll find tabs on the back of this ring protruding toward the back at about 12 and 6 o'clock. Use these to turn it counter-clockwise just a touch, maybe 0.25 inch. It, and the bulb, will now be loose. You're liable to drop both if you're not putting a little forward pressure on them at this point. You can now withdraw the ring. The bulb will be loose, and you can pull it out easily.

    Installation is the reverse. Handle the new bulb only by the rear prongs and/or the metal base between the prongs and glass. There's no need to touch the glass at all. Set the bulb in place in the fixture with the middle prong at the top. It doesn't "snap" in or screw in at all - it's held in entirely by the retaining ring. You'll know it's in the right place, however, when it won't rotate much to the left or right. The bulb's base has three tabs sticking out to the sides in a sort of inverted "Y" arrangement. These tabs fit into the fixture to make sure the bulb is correctly oriented.

    To reinstall the retaining ring, line it up with one of the rear-pointing tabs near the top, just left of 12 o'clock. Jiggle it a bit and you should feel it snug up against the back of the bulb's metal base. You can then turn it that 0.25" or so to the right to lock into place. Replace the rubber boot and plug.

  3. #3
    Registered User
    Join Date
    Apr 2012
    Location
    Los Angeles, CA
    Posts
    341

    A picture is worth....

    Here's the assembled ring+bulb. Rubber boot can be seen removed, at the bottom of the pic:
    RTHeadlight1.jpg

  4. #4
    Registered User
    Join Date
    Apr 2012
    Location
    Los Angeles, CA
    Posts
    341
    And apparently I can only attach one photo per post. So here are the other two pics, showing the ring just removed from the back of the fixture, and the bulb just pulled out.

    Again, the ring doesn't spin around to "screw" in. It just turns enough for those horizontal tabs to lock in behind the appropriate spots in the white plastic/ceramic/whatever fixture.

    RTHeadlight2 copy.jpg

  5. #5
    Dale Rudolph
    Join Date
    May 2009
    Location
    Medford, Oregon
    Posts
    579
    James, Thank you for the reply and pictures.
    I will pick up a new bulb in the morning and get it installed. Thanks to your pictures, I have a good idea what I'm doing now.

    As much as I like the RT model and wouldn't have a bike without good wind protection because of my bad neck, all the fairing parts have made what would be a simple job on a standard K-75 much more
    difficult to do on the RT.

    As they say, "A picture is worth a thousand words". Now that I have seen your pictures, the Clymer book now makes more sence.

  6. #6
    Registered User WalterK75's Avatar
    Join Date
    Feb 2009
    Location
    Mississauga, Ontario
    Posts
    567
    If necessary hold the new bulb with a cloth so you don't get finger oil on the glass.
    Walter

    All government, of course, is against liberty.
    H. L. Mencken

  7. #7
    Dale Rudolph
    Join Date
    May 2009
    Location
    Medford, Oregon
    Posts
    579
    Thanks again James, your pictures made the bulb changing go smoothly.
    I got the old bulb out and tested it on a spare car battery, both the high and low beams worked, the high beam came on instantly and was bright. The low beam that wasn't working while in the bike
    took about 3 seconds to get fully lit. Thinking maybe it was starting to go bad, I bought a new bulb.
    Testing the new bulb, the low beam also took a few second to get fully lit, so I will assume that it is normal and there probably was nothing wrong with the old bulb. I installed the new bulb.

    My best guess now is that the headlight switch should be opened up to check the contacts. I checked IBMWR's website and they have a few threads about cleaning the headlight switch, all say be careful
    not to lose any parts that may go flying out. I'm surprised that there is not a fuse for the headlight.

    I'll go over the wiring diagram in the Clymers and see if there is another plug where the headlight wires from the switch end up and check those connections.

    I ended up having to remove the knee panel and the storage box to be able to get into the back of the headlight, I don't see how it can be done without removing them.

  8. #8
    Registered User
    Join Date
    Apr 2012
    Location
    Los Angeles, CA
    Posts
    341
    From what you describe, it sounds like what I've seen online about dirty headlight switches. The rest of the headlight wiring is pretty straightforward.

    I've taken apart the right-hand switches but not the left. I'll echo what you've read: Be careful. There are tiny springs in there that are very easy to lose. I'd go so far as to say it wouldn't be unreasonable to pick up a used left-hand switchgear on eBay before you go tearing into yours.

    Also, if you do the work inside a cardboard file box tipped on its side (so the open top of the box is facing you), and put a towel on the bottom, you dramatically increase your chances of not losing small parts. The towel helps keep little things from rolling away. It helps to have a small desk lamp handy when working this way.

  9. #9
    Dale Rudolph
    Join Date
    May 2009
    Location
    Medford, Oregon
    Posts
    579
    I did a google search on K75 headlight switches and ended up at a website called MotoBrick, which is nothing but K-100 and K-75. There is a complete story on taking apart the switch with plenty of pictures.
    I registered to be able to get back into their forums and got a reply that I should be able to get logged on by tomarrow.

    If I can get to the end of the switch plug-in, I'll take the switch off the bike so I can open it up at the workbench or kitchen table. There would be less of a chance of something getting away if the switch
    wasn't hanging off the handlebar. I have an old 6 inch speaker magnet, I'll try opening up the switch on top of it, if anything falls out, it shouldn't fo far. Maybe even do it inside of a cardboard box.

    The Clymers book made a point not to touch the lens. I looked at bulbs from three different companies today, not one of them had a warning not to touch the lens. The salesman where I bought the bulb
    said "Don't touch the lens". If touching the lens can cut the life of the bulb in half, I guess that is what they like to see happen. Come back and buy another bulb.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •