Loss of power and running poor

Having Problems with your BMW R1200RT/R1250RT? or have some Maintenance and Service questions?
chrismckay
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Loss of power and running poor

Post by chrismckay »

Just had my 2012 R1200RT out for a blast and had to limp home on reduced power.


The symptoms are loss of power, engine lumpy, engine stalls at decreased revs, engine occasionally backfires.


Does anybody with a greater mechanical knowledge than me have some advice?


Chris... ;D
Last edited by chrismckay on Wed Oct 23, 2019 12:33 pm, edited 1 time in total.
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Boxflyer
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Re: Loss of power and running poor

Post by Boxflyer »

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simbo
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Re: Loss of power and running poor

Post by simbo »

Coil breaking down possibly?
The GS 'is' the better bike :-)
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David.
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Re: Loss of power and running poor

Post by David. »

Are any warning lights showing on the dash.

Are there any unusual mechanical sounding noises coming from the engine.
chrismckay
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Re: Loss of power and running poor

Post by chrismckay »

David. wrote: Are any warning lights showing on the dash.

Are there any unusual mechanical sounding noises coming from the engine.

Hello David,


There are no warning lamps illuminated and no unusual noises apart from running lumpy!
chrismckay
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Re: Loss of power and running poor

Post by chrismckay »

simbo wrote: Coil breaking down possibly?

is there a diy check for this?
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Re: Loss of power and running poor

Post by simbo »

chrismckay wrote:
is there a diy check for this?

Remove each coil in turn and see if it makes a difference to the engines running. When/if you remove one and it makes no difference? That usually leads to the failing coil (ht cap)
The GS 'is' the better bike :-)
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David.
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Re: Loss of power and running poor

Post by David. »

To support the above suggestion by Simbo, here is a video to help the explanation.

https://www.youtube.com/watch?v=hMJWr_BdNO8 OK, it's for a 2004 BMW R1150GS, but the principle is the same.

Not forgetting that the 2012 R1200RT is twin spark, two plugs/coils per cylinder.
Last edited by David. on Wed Oct 23, 2019 9:22 pm, edited 1 time in total.
chrismckay
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Re: Loss of power and running poor

Post by chrismckay »

David. wrote: To support the above suggestion by Simbo, here is a video to help the explanation

Thanks for the information Dave and Simbo.


Nice demonstration of how to check for the ineffective coil. The thing is though that the bike wont idle as it stalls at idle revs. Is it possible that perhaps 2 coils are affected?
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David.
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Re: Loss of power and running poor

Post by David. »

chrismckay wrote:Is it possible that perhaps 2 coils are affected?
Have you got a Haynes manual, there are sections on Ignition system checks & Ignition coils.

If not, PM me an email address and I'll have a go at scanning the page.
Last edited by David. on Thu Oct 24, 2019 10:41 am, edited 1 time in total.
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milleplod
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Re: Loss of power and running poor

Post by milleplod »

chrismckay wrote:
Thanks for the information Dave and Simbo.


Nice demonstration of how to check for the ineffective coil. The thing is though that the bike wont idle as it stalls at idle revs. Is it possible that perhaps 2 coils are affected?
As per Steptoe's reply over on UKGSer, yes it's possible that 2 have failed - you might not notice with one gone, but you do when another joins it!
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Re: Loss of power and running poor

Post by Pabst »

My '18 did that, bmw bought it back, they threw parts at it for 4 months then gave up and gave me a refund.  Check where the throttle plugs in near the grip, make sure it clicks in, sometimes that's all it takes.
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David.
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Re: Loss of power and running poor

Post by David. »

chrismckay wrote:Just had my 2012 R1200RT out for a blast and had to limp home on reduced power.
Pabst wrote:My '18 did that.
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Re: Loss of power and running poor

Post by chrismckay »

Just a follow up to the outcome of the issue.


Turns out that the throttle cable had jumped a pulley...!!
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Re: Loss of power and running poor

Post by David. »

chrismckay wrote:Turns out that the throttle cable had jumped a pulley.
Which pulley was it, twistgrip, cable splitter (on the front of the air filter housing) or throttle body.

Could this have been attributed to throttle cable adjustment/free play.

Is the bike fitted with cruise control.
Last edited by David. on Sat Feb 29, 2020 4:13 pm, edited 1 time in total.
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