I recently bought a used Honda Master Series mower (HR215K1SXA with GXV140 engine). It was lightly used, is in great shape and runs well with one exception: When unloaded, the engine runs at high speed irrespective of the position of the throttle lever. When loaded (by engaging the blade clutch, for example), it slows to a more normal idle speed and responds normally to the throttle. (I haven't really experimented much to see whether this speed is governed or open-loop.) If I press on the governor lever, I can increase the engine speed but not decrease it.

My guess is that the engine's simply set up wrong. I intend to get a service manual for the mower, which should tell me how to address it, but I thought I might be able to get a jump on it by soliciting advice here. Does this ring a bell with anyone?

Thanks,

Fred