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Discussion Starter · #1 ·
I completed a valve adjustment on my 07 zx6r with 13k miles. It ran perfectly fine before but now it has a loud knocking sound that is terrible. I'm guessing it could be the chain tensioner but I have a 2nd complaint. The threads on the hole to spin the crank are stripped, I have it RTV'd to maintain oil pressure (lol) but if I replace the CCT i'll need to rotate the crank for the CCT to adjust properly.

1) What's causing the loud knocking sound, is it the CCT?

2) How can I replace the starter clutch cover? Do I need to split the cases?
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2022 ZX-6R KRT ABS
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Noise sounds like a very loose clearance/s to me.
Maybe a good question is did you (intend to) significantly reduce any shim thicknesses (to significantly increase any clearance)?

That noise is really loud...

I'd be immediately concerned with:
  1. did I leave something (socket, etc.) in the engine?
  2. did I align crankshaft and camshaft properly?
  3. did a shim pop out under a bucket? (or did I put two shims under one bucket?)
  4. did I tighten the camshaft caps?
I think it's immediately worth re-opening the engine...

Did you go thru the whole "valve clearance inspection" procedure before buttoning things up? And did you manually rotate the crankshaft thru at least two revolutions first?
 

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PS probably not much of a surprise, but from the audio track, it's 120ms between knocks. That'd be exactly two revolutions if your idle is 1000 rpm -- pretty much what we expect for anything wrong up at the camshaft -- a 2 revolution period... Did you count your shims (outside the engine) both before and after the procedure?
 

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Discussion Starter · #5 ·
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I can't find my sheet where I measured the old shim and the new shim and done the calculation. It's been 2 years since the valve adjustment I just now got around to dewinterizing the bike.
The intake valves didn't need adjusting afaik.

I feel like it could be valves that are too loose, I may have measured at the wrong cam position. Hopefully my timing is still good and it's just valve guide noise or something like that. I'll be doing a tear down in the following weeks.
 

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Discussion Starter · #6 ·
Maybe a good question is did you (intend to) significantly reduce any shim thicknesses (to significantly increase any clearance)?
I found some of my measurements I think yes, I did reduce shim thickness to increase clearances. Here's for my exhaust clearances:

I did a+b-c=d
a = present shim
b=measured valve clearance
c= specific clearance
d= replacement shim

1.848 + 0.145 - 0.275 = 1.718

So all of the old shims are 1.848 or 1.845 mm. All of the new shims are 1.70, 1.75, 1.65, 1.60.
 

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So you increased clearance by 0.2mm to 0.25mm on two cylinders, and the clearance spec is maybe a third of that?

Your big fear is "first contact" missing the gradual "opening ramp" on the cam lobe -- because the lobe will smack the valve where the lobe is raising quickly, rather than where it is raising slowly.

(I don't know if there are any published camshaft lift curves for these engines -- that would tell you how high the ramp is...)

So possibly you have multiple valves contributing to the noise -- though it looks from the imprecise audio like just one is leading the charge:

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I think you want to open it right up and double-check everything -- I've heard loud before, but never that loud (though it's hard to be sure with a video)...

Pay special attention to your camshaft timing as well...

Rotate the engine by hand thru two full revolutions and look and listen, in addition to measuring all clearances...

PS I'm almost thinking lift each bucket as well, just to make sure there's nothing under one that does not belong...
 

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I found some of my measurements I think yes, I did reduce shim thickness to increase clearances. Here's for my exhaust clearances:

I did a+b-c=d
a = present shim
b=measured valve clearance
c= specific clearance
d= replacement shim

1.848 + 0.145 - 0.275 = 1.718

So all of the old shims are 1.848 or 1.845 mm. All of the new shims are 1.70, 1.75, 1.65, 1.60.
you would have had to have had zero clearance or less to need that much change in shim size!!!

going from a 1.85 shim down to a 1.60 shim is approx.... .010" change.......... it is very rare to need that much change (although I do see it far too often)

1.85 down to a 1.65 is about .008"
1.85 down to a 1.75 is about .006"

I concur with above.............

DID YOU MEASURE THE CLEARANCES AGAIN ONCE YOU PUT IN THE DIFFERENT SIZE SHIMS!!!!!!!?????

I BET SOME ARE WAY TOO LOOSE OR OR OR...........

Stop running it and take it apart and see what is wrong!
 
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