Feels like running on one cylinder??

[horudis82]

Hi there,

I have a R1200gs from 2007 acquired recently, it has been a few days now that the engine feels without torque in low revs, with a knocking sound and irregular acceleration. It gets better after 3000 rpm but does not feel right. Idle is irregular and feels like stalling every few seconds, and when it does it transmits a bad vibe through the gears/clutch (I do not know specifically which one) and I can hear the whole thing knocking as well.

When I bought it I had it serviced, new spark plugs and valve clearances checked, as well as both lambda sensors changed by myself (do they need calibrating?) but it did not show any such weird noises.

I have been on the forum and looked for similar cases and I have seen those possible causes:

- Dead coils
- Air leak
- Valve clearances (but those ones were supposedly checked by the garage)

I am forgetting anything?? I'd like to try everything I can before having to bring to the mechanic...

Thanks for your input guys!
Cheers -

 

[younger06]

Check that both of the throttle bodies are firmly clamped in place. I had the exact same symptoms recently and I found that one of the clamps holding the throttle body in place had failed.

 

[Alan R]

My bike is a 2011 twin cam so this may not be applicable to your bike, but here it is... While cleaning I had dislodged a connector to one of the idle stepper motors which sits upon the throttle body. The resultant rough running was exactly as you describe. Pushed the connector home - smooth (boxer smooth), running restored.
Alan R

 

[horudis82]

Thank you very much for your suggestions guys, I will look into it cheers!

 

[Bendy toy]

Pull the primary coils. If they are the old black painted type and smell of hot insulation they are almost certainly failing.
Mine both went within a few miles. North Oxford BMW said a that's usually how they go.

 

[horudis82]

Quick update: I didn't find anything by myself, as it was time to du a full service at BMW thy checked and found a loose cable (I didn't find it!) on the left hand side on the top of the throttle body. They clipped it back.
Now works as a charm...
I don't understand how come I didn't find it myself...
Thanks for your help guys!

 

[Bendy toy]

Top marks to AlanR

 

[horudis82]

True Thanks Alan R!!

 

[Alan R]

Aw shucks, 'twas nuthin.
When it happened to my bike I couldn't see any thing obvious either, so I connected my gs911 and ran a check that told me that stepper motor no 2 had no value, so I thought that it was defective and decided to remove it to go and get a replacement. It was only then, torx driver in hand, that I noticed the ever so slightly displaced connector. My first thoughts were that one of the stick coils was breaking down. Gs911 - a really useful addition to your tool box
Alan R

 

[horudis82]

Hi guys, after a couple of months the issue is back... I think the cable must have moved again; I want to get this sorted for good - can you recommend a mechanic in south london (who can also fix a brake servo??)

Thanks!!

 

[GORILA]

Depends on where you are. Mark HOLDEN in Bromley of MH motorcycles and Neil HARRISON in South West London of The GS Shop are both very good independent bike mechanics specialising on BMWs.

 

[flatdog]

Depends on where you are. Mark HOLDEN in Bromley of MH motorcycles and Neil HARRISON in South West London of The GS Shop are both very good independent bike mechanics specialising on BMWs.

Neil is 'Steptoe' on here.
http://gsshop.biz/

 

[horudis82]

Thank you very much!!

 

[horudis82]

Hi guys! I'm back with a weird question: have you ever had a knock sensor fail? I'm asking because when I use 95 it feels like a Diesel engine, and when I put premium petrol in it feels like a bike again. Could the sensor be broken and stuck on "97" mapping? Or is it just a lot of carbon build up in the engine?

Thanks!

 

[Bendy toy]

Mine feels crap on 95. I normally use Shell posh or Tesco 99.

I also notice how stinking hot the exhaust downpipes (headers) get when its using 95. Which is fair as the later spark timing will always put more heat down the exhaust.

 

[younger06]

At least you can still get 99ron in the YouKay!!

Sent using hocus pocus........... boo!

 

[Bendy toy]

Hi guys! I'm back with a weird question: have you ever had a knock sensor fail? I'm asking because when I use 95 it feels like a Diesel engine, and when I put premium petrol in it feels like a bike again. Could the sensor be broken and stuck on "97" mapping? Or is it just a lot of carbon build up in the engine?

Thanks!

Chuck in a tank of 99 and go for a had blast until it's empty and repeat.

 

[horudis82]

Chuck in a tank of 99 and go for a had blast until it's empty and repeat.

Thanks for your feedback guys I'm going to use 97 and above o my from now on.

Cheers!