Well, the "issue" wasn't the valves, it was carb balance. Still, good to get a professional opinion every few years.
The loaner was a Bonneville America

. Review with a picture here https://sites.google.com/site/threewheelbonnienonbike/other-bonnevilles .
This thing is 'Orrible with capital O. The feet first controls mean anyone under six foot or with feet bigger than size five will need to wear a cricket box to protect the family jewels from the tank and ballet shoes to get you foot under the gear lever (it needs a heel and toe). Once you get moving it's human parachute time unless you shuffel back onto the pillion pegs , plus the thing has the turning circle of a super tanker. That huge petrol tank is all full of electrics so the light comes on at barely 100 miles. So, what's it good for: It goes 0-40 in a straight line quite well and people who don't know better stare at it. BTW, no one waves to you on this chromed, fake Harley behemoth on a Saturday afternoon, they all think you are a Dentist or Accountant who owns a tassled jacket to wear during the "season". So, conclusion: Pointless.
To conclude with one nice thing to say: The motor is first class, although I still prefer the Bonnevilles 360 firing over the fake V-twin 270 version.
Andy