tapping/knockig noise. HELP, please!

Please, help me to identify source for a strange noise... (and try to understand this text :))

I have vfr800 2003 55000km driven and I have problem with a strange noise. Motor is running well when idle (there is only great smooth sound of Honda engine) but when you accelerate until 5500rpm strange noise appears. I have tried to locate the source for that noise but I'm not quite sure what is the reason for the sound. Probably there is something wrong with the valves, I guess???

Sound is quite strong tapping noise and it occurs even when the bike is in place or when driving. The clutch does not matter for the noise at all. Noise is more stronger if you accelerate until 6500rpm and then make engine braking.  Could it be the CCT (cam chain tensioner) failure???
I have already changed VTec solenoid and rear CCT, but the noise still exist... Tomorrow i'll order also another CCT and change the front one.

Please help, any comments and guess are WELCOME!!!

It's typically the front CCT that makes noise although not always the case.  If you could record the noise and post it on youtube(or similar) it might help the experts on here decide what's going on.

Usually a cct will do it at idle also, But you could have a rare case. If you replaced the rear and it made no difference(for this reason), you might just be able to install the old rear one in the front, its probably okay.

The rear one, normally holds up the longest

Did the 6th gen have an airbox flapper valve like the 5th?? If it did, it could be what you are hearing....

Beck
95 VFR.

[image: View Post]Beck, on 03 September 2012 - 05:03 PM, said:

Did the 6th gen have an airbox flapper valve like the 5th?? If it did, it could be what you are hearing....

Beck
95 VFR.

Yes it does.

Like mentioned the CCT noise is usually strongest at idle, but it's still most likely the source.  Easy to stick a piece of hose to your ear and isolate where the rattle is coming from before slapping more parts on it!

BR

3 words
First word, one syllable :  sounds like Pam
Second word, one syllable: rhymes with main, 5 letters
Third word, 3 syllables: kind of like adding stress, rhymes with pensioner

CCT, do both and enjoy the v4

Similar noise took the mechanics at the dealer I go to about 5 seconds to diagnose.
If you do your own work, your dealer might not be as helpful with the diagnosis as mine was.
FWIW, They did replace both CCTs and the noise is gone.

Yes! Front CCT also changed and the "noise" is gone!!! Thank You all for your help!!!
I also changed oil, Castrol 10W-50 and motor is still more quiet!

[image: View Post]spud786, on 03 September 2012 - 04:35 PM, said:

Usually a cct will do it at idle also, But you could have a rare case. If you replaced the rear and it made no difference(for this reason), you might just be able to install the old rear one in the front, its probably okay.

The rear one, normally holds up the longest

Actually mine never clicked at idle, they only ever rattled when downshifting.   I had three sets rattle that way over 140,000KM