HELP, engine noise, vibration...

[mademiriam]

Yesterday the 'better' half took the bike to work. On the way home it- Stalled twice at stop signs, sounded rough, and made some strange noise. We've both never heard cam chain noise in a bandit but it sounded a bit like that. Also had lots of vibration but evidently evened out over 5000 rpm.
The bike has 25,000 km on it, 3000km since a 'crash', no engine modifications of any kind. The valve adjust was coming due, but up to a couple days ago it ran well. It started making a 'noise' which I deemed suspicious like cam chain noise right after I hit 'something' at speed (most likely coincidence but I mention it because you just never know). Under normal circumstances he would not have taken it to work without us first checking the source of the 'noise'.
The bike does see close to redline often, and hasn't exactly been babied. But its warmed up prior to any antics. It has never (including now) burnt any measurable amount of oil.
Where should I start? What should I look and listen for?

Good thing I just bought a car yesterday...the old bandit has timing.

[Red01]

Well, if it's due for a valve lash check, it would be a good time to look at the plugs and while you have the cover off, you should be able to detect if the cam chain is a source of any of your noises.  What kind of shape is the air filter in?  Could any rough running be attributed to a dirty filter(s)?

[mademiriam]

Well, if it's due for a valve lash check, it would be a good time to look at the plugs and while you have the cover off, you should be able to detect if the cam chain is a source of any of your noises.  What kind of shape is the air filter in?  Could any rough running be attributed to a dirty filter(s)?

Thanks for the input Red, the filter should be clean doesn't hurt to check it imagine if thats part of the reason and here I am thinking about serious engine work. The odd thing is how quickly the symptoms materialized. Thanks also for the link in the other thread for the valve adjust.
Also haven't checked the plugs but just got 4 new ones in could be lucky timing.
Now if only that hardwood floor would install itself and I could tear it apart this weekend...

[mademiriam]

  any other ideas anyone? I want to pull the valve cover this week. So all input prior to getting started is appreciated.

[Red01]

It's easiest to pull the valve cover with the tank off... and it's easiest to remove the tank when it's got less gas in it... so, take it for an enjoyable ride and run it as low as you dare, the day (or more) prior to doing the work.  You want the engine to be good and "cold" when you check the valve adjustment.

[mademiriam]

oh how I wish, he tells me the noise is so bad it should not be started, or run for fear of doing more damage. And of course this has been the week when the weather has been warm... I'll just have to drain the tank the old (and boring) way.
I'll take pictures of anything horribly, wrong...as clearly something is.  I realize now that saying 'strange' noise in my original post probably didn't sum things up very well. It is evidently a near catastrophic 'oh my it's going to blow' sort of noise.
Thanks for the input red I'll keep you posted.

[PitterB4]

Oh shit... that doesn't sound good!  Keep us posted!

[speedwaymaniac]

Damn that sounds very familiar to something i'm getting on my B6. Not so much vibration (not that i can feel) but a horrid rattle at 4000RPM which seems to be gone over that. Let me know what you find when you take it apart, may help me in diagnosing what i do next...

[pmackie]

Hey speedwaymaniac

Most B6's suffer a patch of raspy "resonant vibration" at approx 4500 rpm. I never noticed the vibration much, but everyone who road the bike commented on the change in sound and/or the vibration.

Frequently, this vibration causes something else to vibrate hormonically sympathetically. Cycle Canada commented on the fairing and windscreen vibrating at approx 5000 rpm in their test back in 2002.

Check over fasteners and look for loose vibrating parts on the exhaust, engine mounts, horn, PAIR injection parts, coils, fairing and tank. Usually, something else is picking up the harmonic and vibrating at the same rpm.

For Mademarian...sounds like something more severe, since the 1200 doesn't usually have the same complaints...

[Geoffwhite18]

Hmm. I also recently developed a nice tickety tick tick at 2500 rpm that has been steadily getting worse over time. Now it goes tickety tick tick slap slap slapity tick tickity! LOL!!!

[Red01]

One thing it could be for both of you is a bad cam chain tensioner... while not a "common" malady, they have been known to quite doing their automatic adjusting thing.  You can replace it with another if it doesn't clean up, or replace it with a manual one (the most commonly done fix) and just adjust it yourself from time to time.

The 600 & 1200 use the same manual adjuster and you can get one for $51.95 (US) from APE Racing.

[Geoffwhite18]

Yeah I've thought about the chain tensioner. I guess I really should take it out and see what's up. Mine kinda sounds like a worn valve guide though. I'll check the tensioner and see what's up!

[mademiriam]

I'm hoping it's the tensioner...crossing my fingers.

[mademiriam]

Well finally got some time...valve cover off everything looks as it should...hope to discover more soon. Going to borrow a compression tester just in case. So it's valve adjust (not done yet but on quick check didn't seem far enough off to cause noise like that), compression... after that I have no idea again.

[mademiriam]

very old topic by now, BUT finally got it worked out, I HOPE. Installed the ape tensioner and all went quiet. The stock tensioner does have some of its groves worn to make you think it may have been stuck in one position for a long time. It may have worked just by putting that back, who knows. I lost two months at the end of my season due to this which was bad between a new house and moving somehow fixing the bike never made it to the top of the list till now. BUT at least should be ready for spring.