Engine running but won't switch off by key

KJB · 1 Engine running but won't switch off by key Tue Jul 03, 2012 10:48 am

KJB

active member

Number of posts : 6

Hi,
I have just restored my BMW K100RS (1984) and since the rebuild and changing a rather damaged looking power saver relay for a second hand unit, the bike runs but won't switch off by the key (kill switch only).

Does anyone know if the power saver relay has a part to play in this?

Any help would be greatly received-Kim Beresford

Rick G · 2 Re: Engine running but won't switch off by key Tue Jul 03, 2012 11:00 am

Rick G

admin

Number of posts : 12058

Hi Kim welcome to the forum
The only thing that could do that is a crook ignition switch one of the guys here did a write up on how to get them apart and do a fix. If you do a search in the electricals section I'm sure you will find it as it's only been a few days since I saw someone else posting in it.
Here http://k100rt.aforumfree.com/t2391-ignition-switch

Inge K. · 3 Re: Engine running but won't switch off by key Tue Jul 03, 2012 11:13 am

Inge K.

VIP

Number of posts : 4321

Welcome Kim!
Another possibility is if terminal 86 & 87 are shorted on the LSR,
then the contacts would stay closed until you push the starter button.

KJB · 4 Re: Engine running but won't switch off by key Tue Jul 03, 2012 9:55 pm

KJB

active member

Number of posts : 6

Hi guys,

this is an odd one, so i've ordered a new power saver relay. What's wierd is the ignition will switch on and off as normal, but once the engine is actually running the igniton switch doesn't operate at all regardless of what position it's in.

I don't know if that will fail the MOT test as it is so for £10 i'll try a new relay.

I think you might be right Inge K!

I'll let you know what happens when it arrives on thursday!

Kim

Inge K. · 5 Re: Engine running but won't switch off by key Tue Jul 03, 2012 10:19 pm

Inge K.

VIP

Number of posts : 4321

Does your light turn off with the ignition?
If not, it`s caused by the previously mentioned possible short.

Welded contacts on the LSR would give similar symptoms,
but then pushing the starter button won`t make any difference.
(and your light would stay on).

You could also swap the horn relay and the LSR, as they are similar.
(but the the short could also be in the wiring, close by)

Inge K. · 6 Re: Engine running but won't switch off by key Tue Jul 03, 2012 11:44 pm

Inge K.

VIP

Number of posts : 4321

Inge K. wrote:then the contacts would stay closed until you push the starter button.

Senior moment............forget this one.
If engine is running above 710 rpm, the starter relay won`t close the contacts.

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1 Engine running but won't switch off by key Tue Jul 03, 2012 10:48 am

KJB

2 Re: Engine running but won't switch off by key Tue Jul 03, 2012 11:00 am

Rick G

3 Re: Engine running but won't switch off by key Tue Jul 03, 2012 11:13 am

Inge K.

4 Re: Engine running but won't switch off by key Tue Jul 03, 2012 9:55 pm

KJB

5 Re: Engine running but won't switch off by key Tue Jul 03, 2012 10:19 pm

Inge K.

6 Re: Engine running but won't switch off by key Tue Jul 03, 2012 11:44 pm

Inge K.

7 Re: Engine running but won't switch off by key

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