Knock?

[melloncollie]

I had a new noise this spring at 4k-4500 rpm, any gear.  Sounded like metallic rattling but I couldn't place what it might be.  Thinking it was a new vibration in the fairing or something under the fairing I left it to see if it'd get worse or become easier to spot.  I do also have an exhaust leak at the first slip joints of my Hindle head pipe. 

I put 9k miles on since then (bike just hit 64k) and the noise is about the same.  Just the other day while on a ride it clicked that I heard something similar in a video here at about 2:40 in.  Is that what a knock sounds like on the FJ?  I put a screwdriver to the bottom end behind the exhaust to listen and heard what I thought was a rhythmic tap tap tap but I don't really know what I'm doing or what sounds normal/abnormal.  I also don't think I've heard a knock or pinging before.

So now I'm concerned I've got/had a knock.  But I've also found I can quickly talk myself into issues that aren't there.  Or talk myself into believing a small issue is a larger issue.  Does this sound like it could be a knock or likely a non-issue?  Where do I go from here?  I have an old oil filter I was planning on cutting open tomorrow to see whats inside, but again, I don't really know what I'm looking for as I've never done that either.

Any troubleshooting help, reassurances its nothing, or tips on what to look for would be greatly appreciated.
Thanks in advance.

[melloncollie]

Cut open the filter with an exhaust/tailpipe cutting tool rather than a grinder or saw to hopefully avoid contamination.  Then used a tin snips once the housing was crushed.



There was some sparkle when I squeezed the pleats together.



And some when I pulled the filter material apart.  These were all around the outer side of the filter.  I'd say the largest pieces were smaller than ground pepper.

[Pat Conlon]

Check your carb jetting....are you using an ignition advance rotor?
If you are running #40 pilots, needles shimmed 1/2 step and #115 mains, you should be fine.
FJ's are noisy engines, nothing to worry about.
A common noise we have is, as our engines age the starter chain gets stretched (the starter chain has no adjuster to pick up slack like we have on our cam chain) Now the sagging starter chain drags across the oil jet causing a grinding sound. No big deal. With the updated XJR engines Yamaha introduced a stubby oil jet to fix this condition.
It's a major job to get into your crankcase to change this oil jet.....so we just live with it.
That could be the particles in your oil filter pleats.
https://fjowners.com/index.php?topic=19016.0

[melloncollie]

No ignition mods as far as I'm aware.  I think I have my flatslides tuned well enough but I've been wanting to take it somewhere to see what someone with a dyno can do with it.  I also run 91 octane because its what I have around me that's ethanol free.

I knew from reading the forum that the starter chain is noisy but I didn't really know why.  It makes sense to me that could be the cause of the filter particles, especially after looking at the picture of the old oil jet.

Thanks for taking the time to read and respond Pat.