KZ900 valve shims Machining

Wookie58 wrote:

zed1015 wrote:

Some Ferrari engines (288 GTO etc) use 29mm shims.

They range from 250 up to 490 so i'd say that's a source for quality shims.
It would be nice to know if the buckets were the same dia as the Kaws too as they have a deeper shim recess which could open up the scope for some interesting possibilities.




 

That's about as wildly exotic as it gets, I bet those prices would make your eyes bleed !!!!

A very quick scan of the interweb suggests the Ferrari shims can be had in the US for $20 - $30 each.

Eurospares lists the tappets at almost $49 each. Other places show over $100.

Looks like the 308 and 328 use the same setup.

Wow check this  awitalian.com/product/ferrari-valve-shim-29mm.html/

$9.95  Ferrari Valve Shim
29mm diameter*Please specify in order notes which size (thickness) you need*Sizes: 2.50, 2.55, 2.60, 2.65, 2.70, 2.75, 2.80, 2.85, 2.90, 2.95, 3.00, 3.05, 3.10, 3.15, 3.20 3.25, 3.30, 3.35, 3.40, 3.45, 3.50, 3.55, 3.60, 3.65, 3.70, 7.75, 3.80, 3.85, 3.90, 3.95, 4.00, 4.05, 4.10, 4.15, 4.20, 4.25, 4.30, 4.35, 4.40, 4.45, 4.50, 4.55, 4.60, 4.65, 4.70, 4.75, 4.80, 4.85
 

Ask your local BMW bike dealer.
The K75 and K100 model use the same shims.

He sell shims for 5€ in Germany

www.tills.de/product-320.html?language=de

Some more bikes use the same 29 mm shims.

Honda:
CB750C Custom - 1980-1982
CB750F Super Sport - 1979-1982
CB750K - 1979-1982
CB750L LTD - 1979
CB750SC Nighthawk - 1982-1983
CB900C Custom - 1980-1982
CB900F Super Sport - 1981-1982
CB1000C Custom - 1983
CB1100F Super Sport - 1983
CBX1047cc - 1979-1982

Yamaha:
SRX250T/TC - 1987
XVZ12TK/TDK Venture & Venture Royal - 1983
XVZ12DL/DKC2/DN Venture Royal - 1984-1985
XVZ13DS/DT Venture Royal - 1986-1987
XVZ13DSC/DTC Venture Royal - 1986-1987
XVZ12T/TC/U/UC Venture - 1987-1988
XVZ13DU/DUC/DW/DWC Venture Royal - 1988-1989
XVZ13DA/DAC/DB/DBC Venture Royal - 1990-1991
XVZ13DD/DDC/DE/DEC Venture Royal - 1992-1993
VMX12N/NC/S/SC V-Max - 1985-1986
VMX12U/UC/W/WC/A/AC/B/BC/D/DC/E/EC V-Max - 1988-1993
FJ1100L/LC/N/NC - 1984-1985
FJ1200S/SC/T/TC - 1986-1987
FJ1200W/WC/A/AC/B/BC/D/DC - 1989-1992
FJ1200AD/ADC/AE/AEC (ABS) - 1992-1993
FJ 600
FZ 600
XJ 550
XJ 650
XJ 750
XS 400
XS 750
XS 850
XS 1100
YX 600

Scirocco i think your list is right except some bikes like the Yamaha fj1100 and 1200 and the Honda cbx 1000 and some of the older cb they use 25mm shims



 

Yes, you are right. They have 16 valve engines.
Must be a incorrect chart from seller.

Zed     Did you surface grind the retainers or use a lathe?

MJinCO wrote:

Zed     Did you surface grind the retainers or use a lathe?

I do them on the lathe.
The collets and retainers cut easily with indexable carbide inserts.
I jig them on a valve stem in the three jaw.

Outstanding.  Thanks

It look like that the stems have already being reduced. I was told that .75 mm can be removed and to grind the keepers but how much was removed ?
Compared to Asphalt900 picture, my intake valve  is .24 mm shorter. Right now, I still have +- .5 mm of the stem over the keepers. 

If I remove .5 mm more, with a 2.0 mm shim...I should be withing spec at .088 mm on my thight exhaust valves at .0015'' / .038 mm. If my math are right !  (actual machined shim are 1.55 & 1.64 mm).

Other option: Get an other head.
Question Is a Z1 head is the same for a KZ900 ?


 

Kaw-boy 900 wrote:

It look like that the stems have already being reduced. I was told that .75 mm can be removed and to grind the keepers but how much was removed ?
Compared to Asphalt900 picture, my intake valve  is .24 mm shorter. Right now, I still have +- .5 mm of the stem over the keepers. 

If I remove .5 mm more, with a 2.0 mm shim...I should be withing spec at .088 mm on my thight exhaust valves at .0015'' / .038 mm. If my math are right !  (actual machined shim are 1.55 & 1.64 mm).

Other option: Get an other head.
Question Is a Z1 head is the same for a KZ900 ?




 

Measuring the valves like that doesn't really mean anything.
You need to measure the installed height with the spring seat removed and go from there.
The retainers can be reduced by 1mm and the collets a little more to ensure they are below the stem tip.
The 4.2mm tip height from the collet groove mentioned in the manual is only to ensure that the stock untouched collets do not protude above the stem tip and allow the bucket to ride on them.
Any head from Z1 through to Z1000 mk2 is a direct fit with the only major difference being 8mm exhaust studs up from 6mm on the later heads.

 

Thanks for reply Zed, 

I have 37.80 +- mm on an exhaust valve from the top of the stem to the bottom where the spring sit. Is this how it measured ?
I still have 4.7 mm of stem above the grove.

My KZ head has 8 mm exhaust studs.

Kaw-boy 900 wrote:

Thanks for reply Zed, 

I have 37.80 +- mm on an exhaust valve from the top of the stem to the bottom where the spring sit. Is this how it measured ?


 

Yes! But make sure steel spring seat is removed and you are measuring from the actual head.