Italian tuneup means letting the motor run?

The temp gauge reads about 1/3 of the way between C and H. It never gets above that once it warms up to that point. It's not the warmth of the engine (coolant and oil) but something else, it seems.

A buddy on another forum suggested there are hairline cracks in the sparkplug wires that are closed when the wires are cold, open when the wires are partly warm because the metal expands faster than the casing, thus opening the cracks, and then are closed again when it gets up to full temp because the casing bits then expand enough to close up the cracks.

Doesn't sound right to me.

Thanks, by the way, to everybody for their helpfulness and theories. Maybe I should try to find a local friend who has a Honda and see where they take theirs. But I think we're rare among my friends in owning a Honda (which is odd considering how popular they are and therefore what % of the public must own one). Time to make some new friends, maybe.