BMW K bikes (Bricks)

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1Back to top Go down    Speedometer weirdness! on Fri Sep 01, 2017 11:53 am


New member
New member
Hi all,

My new toy, a lovely K1, has a speedo funny. No speedo at all until it warms up. Then a lazy and erratic reading, frequently vacillating up to actual speed, rarely making it over 40mph though, and often returning to zero for a rest. Sometimes rising as the bike slows, but never exceeding actual (as estimated by me) speed.

Poor connection somewhere, I'm assuming. Would anyone be able to point me in the likely direction?

Many thanks,



2Back to top Go down    Re: Speedometer weirdness! on Fri Sep 01, 2017 12:13 pm


Silver member
Silver member
Follow the wire from the speed sensor on the rear drive up to the connector. You probably have a bad connection there. A spray of contact cleaner may help.

2004 R1150RT 186,800 miles
1991 K100LT 128,700 miles
1982 R100RT 106,900 miles
Total422,400 BMW miles


The cheapest thing on a BMW is the nut that connects the handlebars to the seat.

3Back to top Go down    Re: Speedometer weirdness! on Fri Sep 01, 2017 12:51 pm


Life time member
Life time member
I agree that the most likely culprit is the speedo sensor or its connector.

More common in earlier Ks but there are also connections in the cluster that can become erratic:

Current stable:
86 Custom K100 (standard fairing, K75 Belly pan, Ceramic chromed engine covers, paralever)
K75 Frankenbrick (Paralever, K11 front end, hybrid ABS, K1100RS fairing, radial tires)
86 K75C Turbo w/ paralever
94 K1100RS
93 K1100LT (x2)
91 K1
93 K75S (K11 front end)
91 K75S (K1 front end)
14 Yamaha WR250R

4Back to top Go down    Re: Speedometer weirdness! on Tue Sep 05, 2017 7:04 am


Gold member
Gold member
Is the speedo affected in the same way as it is on the K1200 bricks? In this case a dirty armature in the starter motor prevents a solid earth connection and many of the K1200 components - indicators, lights, speedo - earth through the starter motor. Other symptoms like indicators that won't stay on while riding, or headlights that flicker at certain revs are other indicators that the starter motor armature is dirty however I don't know if the 100/1100's are affected the same way. Until someone tells me...

Current rides:
2002 K1200RS. Owned from new. Pacific Blue, Ohlins, Speiglers, Fiamms, HID. 167,000km
1991 K1. Schwartz metallic black, 18 month frame off restoration. 74,000km
1987 K100RS Style. Black, Ohlins, Race Tech springs, Braided lines. Fully restored. 53,000 miles.
The family history:
1951 AJS 500 single - my Dads ride
1953 Triumph Terrier - my Mum's ride
1916 Triumph Type H, Battle of the Somme, France WW1 - my Grand dads ride

5Back to top Go down    Re: Speedometer weirdness! on Tue Sep 05, 2017 9:49 am

RicK G

AFAIK it is the load shed relay only that earths through the starter all the other components have conventional earth paths.
Many of those components get power through the load shed relay.

"Every normal man must be tempted, at times, to spit upon his hands, hoist the black flag, and begin slitting throats." from Mencken's 1919 Prejudices

Bikes 1993 K1100 LT, 1998 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki X 2 for now

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