Jerky movement low gear high revs?

[flynrider]

When I stay in low gears (1/2) and take the revs up above 2000 and keep it there, the cb has a jerky motion, as if the fuel supply is not constant. The exhaust also sounds 'spluttery'.

Not noticeable in high gears and high speed (eg 100 km/hr in 5th).

Is this normal? EFI related?

6000 km service was 1000km ago, so the chain tension should be within tolerance.

Comments?

Thanks.

I've noticed this on my '13. It only occurs when trying to maintain a constant low speed (around 10-15 mph) in low gear. About the only place I encounter it is riding the last few blocks to work, where there are a lot of speed bumps. I wouldn't go so far as to call it jerky. It's just a little rough. Your description of the exhaust note as "spluttery" hits the nail on the head.

I've always assumed that it was a fueling issue due to emission requirements. Since I rarely spend much time at low gear around 2K rpms I've never considered it to be an issue.