Running Issue

[Billy Bones]

Can anyone tell me why a 05 1200GS breakes up at high RPM's?

[marc]

How high? If your RPM is at or slightly above red line it's probably the rev limiter kicking in. If the RPM is below that I'd check sparkplugs and stick coils. Problems with either sometimes show up as roughness at high RPM.

[Billy Bones]

Thanks, just figured out that the plugs have not been changed since 05.....