surging/missing problem

[Mike Mc]

I have a 09 GSA that I purchased about a month ago and am new to this bike.. It seems that sometimes not always, it seems to surge at around 3000 rpm. I know of the gear lash, but the engine seems to be a little rough.. the bike has 26000 miles on it. one day it does it and the next its smooth. I don't think the spark plugs have been changed.. what do you think? Hard to ride at slower speeds around town.. Thank you for your responses.. Mike

[Wiley]

When were the valves last adjusted? If more than 6,000 miles or so adjusting them along with 4 new spark plugs may improve it a good bit. A coil acting up can sometimes cause what you describe also.

[pdxrmccgs]

There are a hand full of sensors that feed engine condition into the
ECU or Engine Control Unit (Engine Computer). If any of these
are acting up it might show up on a GS911 diagnostic port plug in
test unit.

If no GS911 around guys point to the Oxygen Sensor or Throttle Position
Sensor as possible considerations.

Your local dealers GT1 Diagnostic Computer may show up the
problem..at least in theory.

[marc]

3000 RPM is borderline lugging the engine. Depending upon weather and road conditions you will get some surging or bucking, especially at low engine loads. Paradoxically you can run at a lower RPM if the engine is under some load. The needed extra throttle richens the mixture enough to make a difference.

There are several versions of a device that will make a difference. Google the accelerator or the booster plug.

Or down shift.