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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: K75user1979 on June 17, 2024, 07:25:45 AM
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When I first got this bike running I thought it had 6 gears. When changing gears it will jump from 4 to 6 on the lcd display, could be an anomally with digits not displaying correctly.. has anyone encountrered this before?
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The switch lives on the back of the transmission where it lives a hard life. When it gets old and cracks it will cause oddities in the LCD display, especially when it's wet and water gets in. It does not cause any electrical damage though as it is all ground circuits.
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More here:
http://www.kbikeparts.com/classickbikes.com/ckb.tech/0.ckb.tech.files/gpi/gpi.htm
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If this is a stock instrument cluster, it's electrically impossible for the LCD display to display a "6" or "7". There is circuitry onboard that blanks the display if BCD 110 or BCD 111 is input. Can you please post the gear numbers that get displayed as you move up the gears - 1-N-2-3-4-5?
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Sure, will take photos. I'm aware that 6 wouldn't be configured for in the system so it's likely that the display is a bit wonky for number 5.
I've never seen it change for example after washing the bike, the numbers are consistent in their display.
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When my gear indicator switch went bad, I saw 0, 8 and anything in between at random.
Frank
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If this is a stock instrument cluster, it's electrically impossible for the LCD display to display a "6" or "7". There is circuitry onboard that blanks the display if BCD 110 or BCD 111 is input. Can you please post the gear numbers that get displayed as you move up the gears - 1-N-2-3-4-5?
Theoretically correct but my K1100RS also shows 6 sometimes.
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Pics of neutral, 2,3,4,5.
Forgot 1st
That 4 does not lookj like a 4, come to think of it.. I think that is the only number that is not consistent. It's a minor thing and not going to dig into the problem with no good reason to strip the bike to that level. I;m going to do the clutch splines one day so will attend to the gear switch then.
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That's what we like—pictorial evidence demonstrating the impossible made possible! You'll need to get in there and check that switch. A local shade tree waterfowl has created a useful webpage concerning that little devil (http://www.kbikeparts.com/classickbikes.com/ckb.tech/0.ckb.tech.files/gpi/gpi.htm).
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That is a useful page. Thanks!!
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Based on your photos, I believe the problem lies with your LCD display. The gear selection switch in the transmission is working properly, as is the wiring to the cluster, and electronics on the gear display board. The problem might be corrosion or dirt between the zebra strips on the display and the contacts on the board. You're getting the correct indication for the gear you select but for certain gears (2,4 and 5) you are getting extra segments illuminated, giving you weird characters. Look at this segment numbering image (https://upload.wikimedia.org/wikipedia/commons/e/ed/7_Segment_Display_with_Labeled_Segments.svg). For gear 2, segment F is illuminated incorrectly. For gear 4 and 5, segment E is illuminated incorrectly.
It's possible that cleaning the contacts between the board and the LCD display might help but the operation is delicate and you'd have to take care.
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Theoretically correct but my K1100RS also shows 6 sometimes.
Then, my guess is your K1100RS display has the same problem as K75user1979.
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Back when my K75 was still under warranty and dinosaurs roamed the earth, the gear indicator started reading Chinese. Bad LCD, probably from moisture. Replacing the readout cured it, not sure if it's still available though.
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I've decided to just leave it as is. Not everything is working on this bike anyway such as the fuel level sender in tank. How perfect do I need or want this bike to be?? As long as it's mechanically sound then I'm happy.