First of all, my Honda dealer did not want to put a tacho on the engine, even if I was asking to do it in a tank or just with water hose, to be sure my tacho is working properly.
They checked the plugs and found them a bit oily, so the plugs were changed without my consent. Ridiculous, because the oil on the plugs was only because I ran the engine for some 15 min after replacing the implelor - just forgot to push the choke back
The dealer rang me asking if I want to got for a full carb cleaning (apparently standard Honda procedure when the plugs are found oily) at £180.00 - I said no way, so the dealer charged me for the plugs replacement only (?!)
Definitely not a dealer I will see again.