Lumpy is defined as as if engine is missing. I am told it is because the engine is run so lean it does this. When trying to maintain a constant speed in traffic it is as if a plug is misfiring, open it up it is fine.
Does anyone else suffer with a lumpy engine when throttle is in no mans land, when in a constant speed in 30mph restriction. Dealer has had bike three times to put right, I am told characteristic of the engine.
