My CBF600 has clocked up just over 30,000 miles and has been serviced by the book (if not better than) for its entire life.
I changed the oil a few weekends ago and did a few hundred miles, all was normal, the engine sounded just right, nothing out of the ordinary at all.
Went out for a ride today in the lovely weather and noticed that it just doesn’t sound the same, before there was more of a whine to the engine noise, and today it just sounded flat. (carbs are perfectly synced)
My suspicion (uneducated ish) is that as its nearing its second valve clearance check, that the loss of noise is perhaps something to do with the valve gear?
Im going to take it out again tomorrow and see if it still sounds off.
What im essentially asking is, would the fact that its nearing and almost definitely needing new shims, affect the noise.
(valve service is at 32k)
Can do, but I’d be surprised if you noticed.
These things tend to be gradual declines you don’t notice until after the service.
Maybe you are getting older and have not been as assiduous with your hearing tests as your service regime.
have you changed your crash helmet lately?
how do you know the carbs are all in balance?
Change in the weather can make a huge difference to how carbed engines run.
Could be that.
beacause i synced them a couple of weekends ago. perfectly flat now 
same helmet and everything, done loads of miles on it since i noticed the ‘change’ and it sounds normal to me now.
im going to whip the cover off and check the clearances at easter when im home from uni and see if it needs shimming
im only 20! so i’d like to think my hearing is spot on :w00t:
20 but a student.
Been to many clubs over the last year?
im a club tech/noise boy, i take my hearing protection really seriously and wear earplugs all the time. nothing wrong with them… honest! 
recommend acs moulded ear plugs to everyone on bikes and at work! bloody amazing things
