TOPIC:

This weekend I decided to do a couple things to my KZ1000. (regrettably) I ordered a Liska top idler & APE spacer blocks that I wanted to install, as well as double check my valve clearances. (I have only put a couple hundred miles on this engine since rebuilding it, and it had been running well.) Clearances all checked out, within .07 - .09 mm across the board. I started up the engine after installing the idler, to sync the carbs since I had removed them to make things easier. I started the engine up and it was very rattly sounding from the cam cover area. Never heard that before.... so I shut it off, and took things back apart, thinking that I did something wrong during reassembly, or maybe dropped something in the head and didn't realize it...
THIS is where shit gets weird.
Everything looked okay from first glance. For some reason I thought to recheck the cam timing, and thought that the lobes looked off center at 1/4 TDC. So I ended up taking them out to do the cam timing over, and I have been screwing around for hours trying to get it to look right, and I simply cannot. When I set the cams in, exhaust cam arrow level with head surface, 28th pin on the intake cam mark, etc. it looks right. When I put the idler back on, set the (APE manual) adjuster snug, and rotate the crank, it ends up looking like this at TDC. Not off by much, but not totally centered. WHAT THE HELL!? I have done it over half a dozen times and can't get it right. The last thing that happened, is that I found my #2 cyl. intake valve shim broken in half. Icing on the cake. Anybody have any ideas for me? I'm about ready to burn my garage down with this damn thing in it. Thanks!

After turning engine over, here is where my exhaust cam mark is... the red paint marks the next pin up from the mark.

....JUST off center at 1/4 TDC

I saw the top of this shim and thought it had a big deep scratch in it- it came out like this.

Sounds like something went bump inside the motor to me anyway.

Man, it sure is making me wonder. I didn't hear anything that sounded like "bad contact", nor should there have been... when it boils down to it, all I changed was the top idler. It was fine before that??!!

If the top idler changes the camshaft chain position even slightly, it changes the position of one camshaft relative to the other. If you keep seeing one cam aligned and the other slightly off, it sounds like the new idler is moving the chain more (vertically) than the old one did?

Was the cam chain checked for stretch service limit?

The broken shim: my shims are only surface hardened so they should not shatter like that, very bizarre. Are they all Kawi OEM shims or aftermarket?

If the cam timing was off significantly, I would have thought a valve would get bent not a shim broke.... weird.

I tried to do this one more time. Same exact thing. Everything looks perfect setting it up, tighten everything up, turn it over a couple times to get back to 1/4 compression TDC, and it doesn't line up perfectly anymore. To complicate things further, if I turn the crank a little past what the advancer says is T, then it will line up perfect.....

If the "correct" position for the camshafts is slightly off with respect to the reference crankshaft position, doesn't that mean there has to be some stretch in the cam chain? I don't know how else it could be off unless a can gear had moved on the shaft..

I did not check the chain to make sure it isn't stretched, but maybe that is the case? This last time that I just put it all back together, I noticed that with the chain adjuster off (uninstalled) the top idler does not even contact the chain. It doesn't touch the chain until I install and tighten the adjuster.... is that normal? I'm sorta thinking no..

The shim was a new aftermarket one that I picked up at my local shop. Clearance was right, and I saw no other damage

Its almost like something was holding the shim off of the bucket in order for it to snap in the center like that.
Id say its time to pull the head off for a quick looksee at that valve.

looks like intake cam is retarded one tooth behind the crankshaft.
when the piston passes tdc, as does the mark, before the intake lobe is
in its correct spot in rotation/relation to the crank, the cam is behind.
When the engine is ran with the intake cam one tooth behind, there will be
much rattling, will rev slowly and basically sound really sick. Its a scary experience
wondering if you broke anything. An objeect lodged in the valve train that would do
that to the shim its luck of the draw the engine didn't grenade. Definitely could
stretch the chain but both cams would be effected if it was lengthened in two spots.
The chain can be rotated 180deg. and the timing can be alighned to determine.
I'm inclined to believe the chain took up the slack and is now stretched and the
problem will soon be of the past as is any further damage occurring.

bountyhunter wrote: If the "correct" position for the camshafts is slightly off with respect to the reference crankshaft position, doesn't that mean there has to be some stretch in the cam chain? I don't know how else it could be off unless a can gear had moved on the shaft..

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bingo

When ever you remove cams and put them back in a shim can move out of the seat and needs to be checked when your done. The shim was not in place all the way and just split instead of being kicked out so consider your self lucky.