KZ900 valve shims Machining

TexasKZ wrote:

Running without a shim could leave those marks as well as damage the cam lobe.

No doubt...You're right, the shims were most likely dislodged from the bockets and the cam lobe has made those marks.
The head had to be replaced because no damage noticed . The cams look good...probably replaced too !
 

zed1015 wrote:

TexasKZ wrote:

Running without a shim could leave those marks as well as damage the cam lobe.

+1 on that.
That bucket has been run without a shim.
Most likely a ground shim shattered and was spat out.
I would advise replacing any buckets with that damage.
The indent /trough on the bucket caused by the cam will leave a void under the replacment shim which could also cause that one to fracture as well.

Thanks for the head ups ! I verified  with my gauge and it is find and the shim move freely but I will order a new one anyway. Note: I have replaced the one with the tacks weld inside.

 

Rolf1976_KZ900 wrote:

regarding shim buckets on the z900  i heard somehwere that on some z900 the buckets came with a void from factory that made shims crack.They was later replaced. Do you know anything about that ? and is it anyway to identify the buckets that is good ?

Yes! 
The early Z1 buckets had a small dimple in the center which caused the shims to crack and were subject of a service bulletin so they should have all gone in the dealers bin years ago..
Their replacements and subsequent buckets on all post Z1 engines just have a smooth plain surface with no indent and cause no problems.

 

When I picked up my oct 72 Z1 9 (WITH 12,000 MILES) I was surprised to find it had the original buckets which I changed out with an engine rebuild.

Kaw-boy 900 wrote:

The head and valves are back from the machine shop, Sterms, springs retainers and keepers trimmed.  Valves shims are 2.70 - 2.80 Ex and 2.55 - 260 mm. (2 of each from Zi Entreprises set) I'm happy with the results. Now waiting for new valve seals.

It look like the previous owner or his mechanic had issue with thin shim !  There is 2 bucket like this. What else can make this kind of marks ? 

 

 

The imprint on the bucket looks like some wanna be genius mechnic add a cut out thin sheet metal of a beer can to adjust the valve lash. 

Scirocco wrote:

The imprint on the bucket looks like some wanna be genius mechnic add a cut out thin sheet metal of a beer can to adjust the valve lash. 

Let me measure it...wont surprised me at this point...LOL. 
The sharp gauges around the external perimeter make me belived that was caused byt a FU*King machined shim cracked and /or spilled out of his nest ! I can imagine the rest of the story,...wrong valves keeper got out, valve hit the piston then kick out the bucket shim and a ''NOT' funny noised happened ! Look that it happened at start up....my 2 cents !






 

Kaw-boy 900 wrote:

The sharp gauges around the external perimeter make me belived that was caused byt a FU*King machined shim cracked and /or spilled out of his nest !

The gouges around the perimeter of the bucket were caused by the edges of the cam lobe once the shim had gone and without the shim the cam lobe also wears a groove on the bucket surface.
If you measure the width of the imprint you will find it matches the width of the cam lobe..

zed1015 wrote:

Kaw-boy 900 wrote:

The sharp gauges around the external perimeter make me belived that was caused byt a FU*King machined shim cracked and /or spilled out of his nest !

Hey Zed  I understand, a picture is worth a thousand words !

The whole surface are smooth, What do you think about it
 

 

 

There is no more sickening sound than "mechanical love making

Whatever shop worked on that engine should be shut down

Kaw-boy 900 wrote:

zed1015 wrote:

Kaw-boy 900 wrote:

The sharp gauges around the external perimeter make me belived that was caused byt a FU*King machined shim cracked and /or spilled out of his nest !

Hey Zed  I understand, a picture is worth a thousand words !

The whole surface are smooth, What do you think about it
 

 

 

No problem using that cam.
I'd just dress back the chipped edges to remove the sharp edges and any loose chips and it's good to go.
 

I wonder how many cam chips and loose pieces of shattered shims are still floating around inside that engine?