Ive owned the bike from around 12,000 miles. It is now on 18,000 and I dont know when the valves have been set, I just know not in my ownership.
Does anyone have any tips on doing it? I've heard most use the 'JPaige method'. Which involves doing the adjuster screw all the way in and then unscrewing it a set amount of times, as the pitch in the thread and therefore the width of the gap can be accurately calculated based on that.
Ive also heard the adjuster screw is also a weird erected oblong shape so you need a special tool to adjust and hold it in place.
If anyone knows a trustworthy mechanic in the midlands I'm all ears. Another thing Ive heard is many mechanics will just listen for any odd noises and not even check the valves, but still charge you for it.