Rough running below 2000rpm

[Guest Rob]

This developed whilst out on a long run. Engine lumpy at low revs with occasional missfire. Smells a bit of petrol at low revs too. To try and sort it I've changed the plugs and noticed pots 2 and 3 were very sooty. Therefore I also changed the coil. Then I tried some fuel additive to clean the injectors. All to no avail! Air filter a bit mucky, could try that. Oh yes, and an odd 'pulling' sensation at high speed like it's cutting power briefly on occasion. ECU perhaps? Any thoughts anyone?

[x11r 386]

Sounds like water in the fuel to me Rob

[Guest Rob]

Well I've had at least three top ups since it started, and all at different stations so I'm inclined to think it's not that.

[blueboy 138]

Yes but water would keep to bottom of the tank so may be worth draining tank completely and trying again certainly cheaper than going down the ECU route yet.

[Kenko 335]

I  would go along with John on the water being at the bottom of the tank, happened to me years ago on a BMW K100LT with exactly the same symptoms.  

[x11r 386]

Yes the Lads are right I had it last year , only way to get rid of is to drain the tank discard that fuel.

[Guest Rob]

Well thanks guys I'll give that a try then and let you know.

[x11r 386]

Also with the amount of ethanol in the fuel now it makes the fuel absorb the water so it doesn't just lay in the bottom of the tank any more.

[Guest shaun2007]

I wish I could claim to have figured this one out but some very clever type did somewhere.

 

My recently purchased bike did all of what you described, rough at low revs, petrol smell, middle two plugs sooty and also, both cats really hot.

 

In my case it was the fuel pressure reg that lives on the end of the fuel rail. Piece of cake to chnge but slightly pricey at just over £104

 

But at least its fixed now, what an engine