Black deposits on pistons

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KzChop82 wrote:

Nessism wrote: The valve seal is fine. I wouldn't bother testing it with the head sidewise.

Did you measure the valve seat width yet? Spec is 1.2mm max. If the seat width is too wide the seal won't hold up with mileage.
www.harborfreight.com/6-inch-digital-caliper-47257.html

I measured off the valve, not the seat. I can only assume they will be identical, correct?

Yes, should be the same. Did you measure the width of the lapping pattern? If so, that's a good way to measure.

swest wrote:

Hey man, Kawasaki publishes service requirements for a reason. If you want to disregard these requirements fine, but hopefully you have a well considered reason.

Times up, pencils down. :whistle:
Steve

Nessism wrote: ...Did you measure the valve seat width yet? Spec is 1.2mm max. If the seat width is too wide the seal won't hold up with mileage....

Yes, and is consistent with the FSM for 1977~1979 KZ1000. But I don't have an FSM covering the 1982 kz1000 csr M2.

The mating surface between the valve seat and valve head (i.e., valve/valve seat contact area) is the valve seating width.

The valve seating width is supposed to be even around the circumference.
Face-cut-width on the valve head is supposed to match face-cut-width on the valve seat.

If too wide, the seating pressure per unit of area is reduced, which may result in compression leakage and carbon accumulation on the seating surface.

If too narrow, heat transfer from the valve is reduced and the valve may overheat and warp.

Uneven seating or seat damage will cause compression leakage.

For example, valve seat width for the KZ1000 is 0.8~1.2 mm.
To measure it -- Remove the valve, apply machinist dye to the valve seat and use a lapper tool to tap the valve lightly into place. Then remove the valve and note where the dye adheres to the valve seating surface.





The valve guide must be in good condition for the dye test so the valve won't wiggle inside the guide.


In comparison, Z1's valve seating surface width service limits are 1.0~1.5 mm.


Good Fortune!

So- would new valves provide a thinner (proper) seat width?

KzChop82 wrote: So- would new valves provide a thinner (proper) seat width?

Perhaps, if the seat was already perfect, and the existing valve faces are beyond restoration. The new valve's perfectly smooth and presumably 45° cut would nestle inside the perfect seat whereby the contact area would be within spec and neither too thick nor too thin.

Much may be learned about the valves, valve face, head thickness, stem length, seat angles and seat-cutting tools, specs, service limits, etc., by downloading the Z1 FSM from KZr's FILEBASE:

click here > www.kzrider.com/filebase/search/finish/1...asaki-service-manual

Start at page 77.






If there's sufficient valve-head thickness, the existing valves (if unburned and uncracked and unbent and otherwise restorable) may likely be re-ground, and stems tipped if needed to gain additional clearance, without needing to be replaced with new valves, whereby the existing valves will have regained their as-new 45° faces..
Basically, the valve face is designed to have a 45° cut, which grinding should produce, along with restoring condition of the face. This 45° surface on the valve face is what mates against the 45° surface in the seat.

The valve seat (incorporated into the engine head) has several angled surfaces, one of which contacts the valve face, to form the contact area between them when the valve is seated in the seat (which is the spec size or too thick or too thin reference in the earlier posted diagram).

Valve cutter tools mentioned in the FSM are used to re-surface the angular cuts in the valve seats -- not used to cut the actual valves themselves.
I suppose it would be correct to say that seats are cut and valves are ground.

If the existing valves are in decent condition with smooth 45° faces, perhaps cutting/resurfacing the seats would produce a thickness of the measured contact area seating width to within specs as provided in the FSM covering the 1982 kz1000 csr M2.

Apologies for where there's repetition of what's already been mentioned and better said by other members in earlier posts.

Good Fortune!

This thing has mushroomed from a simple head gasket to a full blown overhaul. Everything looks good to me. I'd put it back together and ride the piss out of it.
Steve :woohoo:

But Steve it's like an oil thread you know 20 page's
over 10w40 or 20w50.
Hell 10 page's about just lap the fuckin valve's and go ride the damn thing

:whistle: :woohoo:

So, is it 10w 40 or 20w 50?