1997-1998 Yamaha GP1200 Idling Rough

1998 Yamaha GP1200 Idling Rough

1997-1998 Yamaha GP1200 (GP-1200) idling rough refers to when the jet-ski’s engine runs uneven or erratically while out of gear or disconnected from a load. It could also mean the engine idle speed is too high or too low, which can result in a loss of power.

Achieving proper idle is critical for good performance and it’s important to fix an idling issue immediately. The following information should help you identify and fix a rough idling condition on your 1997-1998 Yamaha GP1200. Check for one or more possible malfunctions:

Idle rough or erratic. 

  1. Idle speed incorrectly adjusted.
  2. Restricted or plugged low speed fuel passage.
  3. Air leaks in the jet-ski’s intake tract.
  4. Throttle linkage sticking or worn.
  5. Ignition system problem.
  6. Improperly adjusted low speed mixture screw.

It’s recommended you refer to the downloadable 1997-1998 Yamaha GP1200 factory service manual for additional idle information. The manual also goes into further detail in regards to what’s discussed here.


    • Adjusting steps: GP1200

      1. Rotate out the idle adjustment screw and stop when its tip is apart from the throttle lever. You should record or mark the set position of the idle adjust screw before you continue.
      2. Loosen the screws.
      3. Tighten the screws.
      4. Rotate in the idle adjustment screw to the set position.

It makes more sense when you’re looking at the diagram in the service manual. Would post a picture but it doesn’t let me.

Leave a Reply

Your email address will not be published.