Another K bike instrument cluster problem

[terham]

I'm having an intermittent problem with my '87 K100RS speedometer/odometer that only seems to occur in colder temperatures. I searched the forums and couldn't find this problem.

I bought this bike last summer and had no problems but in the fall noticed on early morning rides the instrument glass would fog and the speedometer was erratic. I've since learned this is a common problem. I had this problem throughout the fall and early winter, and then put it away for the winter. No Rounder membership for me. :cry I went out yesterday and for the first time the speedometer didn't work at all and the trip meter and odometer were way off. The temp was in the mid 40s. I went out later in the day with the temps in the low to mid 50s and the speedometer/odometer worked more times than not and today the temps were in the 60s and I had no problems. Is the temp a red herring and this is the same ole problem? Anyone else had this problem? As the temps are starting to warm up here in PA I'm hoping I can ignore this until next fall and add this my winter "to do" list. BTW, the bike is garage kept and doesn't see a lot of rain - true for PO also.

[gsmetal]

I have a 93 K1100LT and this spring (first spring for me with this bike) the speedo showed 20 mph no matter how fast I was going. Even the tach wasn't working right.

Now with temps in the 60's it's back to working fine.

I have had 3 other K bikes and I have had some type of problem with all 3 bikes. My wife has a 87 K75 that doesn't have any problems.

Don't bother taking it apart - you won't be able to fix anything.

This is an annoying problem on otherwise a great and spectacular bike.

[Burnszilla]

In the early 90's they redesigned the speedo/tach case by adding a gore-tex-like membrane on the back for breathablilty. You can buy the new gauge case for around $200 from a dealer and just swap the guts. You can also look on ebay for someone who is selling the newer style gauges with the vent, with a broken tach or something, which will drive the price down.

good luck.

[breyfogle]

Don't bother taking it apart - you won't be able to fix anything. This is an annoying problem on otherwise a great and spectacular bike.

"Fix" is relative. I long ago accepted that Speedo maintenance was a k-bike fact-of-life. Every 12 to 18 months, my speedo begins to get errartic. If it happens during the Spring Fog season, the speedo will just get worse until its unusable. If it happens to be Summer, I can postpone the inevitable repair work until the Winter.

The root cause is micro-corrosion on an internal electrical connector inside the Speedo housing. Cool and damp is bad, warm and dry is better. The "Fix" is to remove and disassemble the speedo housing, clean the three pin connector (even if there is no visible sign of corrosion), reassemble and reinstall. It really is easy to do and there are no shortage of "how-to" instructions on the WWW.

[roy]

Terence, if you have a good local dealer they should be able to print out some factory service bulletins on suggested repairs for early K-bikes. I bought my 85 last October and it was doing the same thing you are describing. If memory serves me correctly there was 3 or 4 different service bulletins the local technician gave me. NOTE: These may NOT apply to your bike since I believe they were issued in 87-88 time frame.
One of them was on where and how to drill a 2mm hole in the back cover to allow some ventilation in the instrument cluster.
Second was on modifying the circuit board to help reduce vibration strain on the speedo contact pins.
Third was on the fuel indicator idiot lights.
Fourth don't recall

Try looking at the www.ibmwr.org/ktech pages. Their are several articles dealing with this problem.

P.S. If you tear the instrument cluster apart plan on buying a new O-ring to seal the cover back in place. About a $5 item

Happy wrenching

Roy

[bmwmick]

I have a 93 K1100LT and this spring (first spring for me with this bike) the speedo showed 20 mph no matter how fast I was going. Even the tach wasn't working right.
Now with temps in the 60's it's back to working fine.
I have had 3 other K bikes and I have had some type of problem with all 3 bikes. My wife has a 87 K75 that doesn't have any problems.
Don't bother taking it apart - you won't be able to fix anything.

GS,
There are two possibilities for your problem (and these gauges CAN be fixed) :)
If you clean the plastic lens with a dry cloth, you CAN build up a static charge on the lens and the needles will 'stick' in various places. A good cleaning with an anti-static plastic posish (I use Novus) will fix that problem in a flash.
The other possibility for sticking needles is the black overlay that covers the face of the gauges. My tach would intermittently fail and stick at about 4,000 RPM. After the dealer replaced one Tach under warranty I found the 'real' problem. The overlay was lifting slightly when it was in direct sunlight. I found that if it stuck, I could shade the Tach with my hand for about 30 seconds and the needle would begin moving again. I removed the overlay and spread a very thin coating of clear silicone RTV on the back of it and re-installed. Now at 132K miles, I've never had another problem.
I've calibrated my speedometer too. It's now extremely accurate at 45MPH and varies very little from actual speed between 10 and 80MH. There are lots of ways to calibrate these but I like the 60Hz transformer method (hold a Soldering gun or other transformer near the speedo pickup in the final drive with the ignition on, bike not running to test). See ibmwr.org K-bike articles for details. http://ibmwr.org/ktech/speedo-cal3.shtml

HTH,