VStrom 1000 =2007 - coughs and is lumpy between 3k and 4k rpm

[rsitch]

Hi group
Having just bought a V Strom 1000 - 2007 - 40k miles - well looked after, I just wanted some feedback on an issue I am starting to experience.
Between 3k and 4k rpm the bike is 'lumpy',. coughs, and does not respond well to throttle increase. After 4k rpm its fine. I bought it with a good service history. It has aftermarket exhausts and a Power commander fitted. Perhaps these maybe a factor ?
Having just sold an SV1000, I am familiar with the twin engine, and the SV was fine through the rev range.
Any wisdom that you can share with me would be appreciated.
Cheers

[Fat Rat]

 

They can be a little lumpy at low revs. Assuming everything is set up correctly (TPS for example) you might want to consider a Power Commander or similar.

[kwackboy]

 

The older 1000s are known for this issue. If you have a power commander already fitted it's likely the previous owner uploaded a generic map which in some cases do work but not every bike is the same.
 
If all is well with other components and there's no obvious faults which you should check first, I'd suggest a custom map done on a rolling road, it's costly but will be totally unique to your bike.

If the dyno technician is any good, he/she/they/it/them will iron out any issues.

[rsitch]

Many thanks for your responses Fat Rat and Kwack boy

[Dr Evil]

I had a 2008 1000 with power commander and generic map ( I assumed) Had the same prob with the flat spot and lumpiness !
I found tweaking the adjustments on the power commander via the screws on the front made a difference until it ran a lot better.
The MPG suffered a bit, but I'd rather it run smoother.

[Gert]

   What brand is the aftermarket exhaust and model power commander (PC) is on your K7 Vee?  PCIII or PCV or PCFC?
 I recall reading of some exhaust manufacturers who do offer a recommended PC map for their specific exhaust per model motorcycle installation.
   Another option would be to see whether the Dynojet website doesn't list a suitable map for your brand of exhaust and PC model?

[The Doctor 46]

I'm not a mechanic but I wonder if this model has a lambda sensor, did I spell that right? If it does then maybe this could be the fault. This is a question to the more knowledgeable on here rsitch, someone will answer soon then we'll both know the answer.

You said you are starting to experience this problem. Did the bike run properly with these aftermarket things fitted when you bought it? Is it possible to ask the seller if he/she could throw any light on the subject?

Another thing that came to mind is, as the aftermarket can was fitted before you purchased the bike, were you given the original can too and if so, why not fit it then disconnect the power commander and see how it goes then?

Good luck with it anyway and don't forget to let us know what the fault was when you know. 

[Rixington43]

The K7 does indeed have a lambda sensor as OEM.
As others have said, do the basics first, TPS adjustment, throttle body sync etc.
Mine has after market cans but no power commander and ran a bit rough lower down when I first got it. Turned out to be a combination of an exhaust leak at the rear downpipe (pre lambda sensor) causing it to run insanely rich and the throttle bodies being pretty far out of sync. Runs much smoother now with no further after market mods such as TREs, Booster Plugs or Power Commanders.

[Hugo Magnus]

Sounds like the exhaust valve sticking, they cut in at around 4,000 rpm (something to do with the emissions) I cut mine out on the Multi.

[kwackboy]

Power commanders require the lamba sensor to be disconnected because there's conflict between to two.

There should be an eliminator fitted of some sort .