Changed the plugs and air filter on my XXY today. Thanks Toni for sending the stuff so prompt. All pretty straightforward by following these instructions, although a lot longer than 45 mins to complete.
Also treated myself to a set of vacuum gauges. The readings weren't that far out, so only a little tweak was needed to have the motor really humming.
The Honda service manual that I have says to disconnect the PAIR hoses from the reed valve covers and to plug the covers when checking/adjusting the vacuum pressure. Does anyone know why? It would make the job considerably easier if they could just be left alone.