Odd Tap/Knocking Sound (Recently Checked Valve Clearance)

[BobDruer]

Hey guys,

I had a look around before posting but I recently changed the variator, clutch & belt on my 2010 Agility, (approx 9,700km in - have ridden maybe 30km since the change) and since doing so have noticed an odd tapping sound (see video for example - ) at first I thought it was a valve issue and after a very slight adjustment to one valve the sound has not changed.

It does not sound like the noise is coming from the CVT area (though there is a slight rattle and whistling sound when under acceleration - no noticeable performance issues though) So I am wondering what it could be and if anyone else had ideas before I got tearing the scooter apart again looking for a cause.

Any help would be awesome, and happy to answer any questions that might help diagnose things.

[CROSSBOLT]

I must ask a basic question, insult is not intentional, but are you absolutely, positively sure the cam was in the right postion for valve adjustment/checking? The audio on your video was the tip-off.

[eamartin]

Sounds like a tap (not a knock).  Could be the drive system was louder before, drowning out the current noise tap.  I'd ride it some more, paying close attention to the noise, although adjusting the valves again would be pretty a simple procedure, as you know.

[BobDruer]

No offense at all taken guys, I'm pretty certain the cam was correctly positioned, aligned the markings on the cooling fan with the fin on the engine case, checked the cam wheel "hole" was facing away from the cylinder and made sure the valve arms had a tiny bit of movement.

I'll have another look at the valve clearances this weekend and grab a few photos while I'm in there. If also thought it might be the valves themselves as they open and close, but didn't want to take things apart that far if it was likely something else!

[Stig / Major Tom]

No offense at all taken guys, I'm pretty certain the cam was correctly positioned, aligned the markings on the cooling fan with the fin on the engine case, checked the cam wheel "hole" was facing away from the cylinder and made sure the valve arms had a tiny bit of movement.

I'll have another look at the valve clearances this weekend and grab a few photos while I'm in there. If also thought it might be the valves themselves as they open and close, but didn't want to take things apart that far if it was likely something else!

Yep, sounds like you were in the correct position for a valve check.
Hope you get it sorted.
Otherwise - as my late brother used to say when mechanical noises were a puzzle, "turn up the radio and press on"
(have you tried the ol' screwdriver held against suspect area and your temple?) (pointy end on the scooter!) (cause I'm not sure I hear anything- off?)
Stig