Head Crack

4TheKZ1000
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Head Crack

15 Nov 2012 22:24 - 15 Nov 2012 22:44

On my old MarkII cyclinder head....I have a crack between the valve seats on one cyclinder (see pic) is this head scrap or can it be used. I had a well known engine builder tell me its ok to use...whats the forum think.....?

Also....its a complete head....any value or take to scrap yard.

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Last edit: 15 Nov 2012 22:44 by 4TheKZ1000.

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Motor Head
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Re: Head Crack

15 Nov 2012 22:32

#558559

They can be repaired of course, but the cost compared to a good head, that's the issue.
I'd chose either before running it that way, as the seats can come loose, possibly causing piston and valves to hit. Could be Ugly, if the piston breaks, :sick:

1982 KZ1000LTD K2 Vance & Hines 4-1 ACCEL COILS Added Vetter fairing & Bags. FOX Racing rear Shocks, Braced Swing-arm, Fork Brace, Progressive Fork Springs RT Gold Emulators, APE Valve Springs, 1166 Big Bore kit, RS34's, GPZ cams.
1980 KZ550LTD C1 Stock SOLD Miss it
1979 MAZDA RX7 in the works, 13B...

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4TheKZ1000
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Re: Head Crack

15 Nov 2012 22:36 - 15 Nov 2012 22:36

#558561

Oh by the way....nice plug repair....some hack worked on it.... :sick: :sick: :sick:

Last edit: 15 Nov 2012 22:36 by 4TheKZ1000.

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gpz1170
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Re: Head Crack

15 Nov 2012 23:50

#558580

Contact John Pearson quite sure he can help

don

1974 Z1
1976 KZ900
1978 KZ1000
1981 KZ1000
1983 GPZ1100

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wireman
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Re: Head Crack

16 Nov 2012 03:13

#558599

Unless its had a lot of money spent on a porting job in the past id say theres nothing special about it ,just hang on to it if you needs parts like fin pieces to weld on to another good head.
Ebay is full of those ugly 79-80 smog motor heads,yeah I prefer the looks of older ones myself! :laugh:

posting from deep under a non-descript barn in an undisclosed location southwest of Omaha.

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APE Jay
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Re: Head Crack

16 Nov 2012 05:28

#558603

Most of the KZ heads that come thru the shop are like that. Unless you are turboing it of running big nitrous load, you won't have a problem with it.

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LarryC
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Re: Head Crack

16 Nov 2012 08:49 - 16 Nov 2012 08:51

#558610

APE Jay wrote: Most of the KZ heads that come thru the shop are like that. Unless you are turboing it of running big nitrous load, you won't have a problem with it.

I received photos just the other day from someone asking that question....I gave the same answer.

Generally I see that on old 900 heads and not on the 1000 heads.

I've never seen the cracks cause a problem on any n/a KZ. Those seats are not going to fall out. That's for dam sure...

Larry C.

Last edit: 16 Nov 2012 08:51 by LarryC.

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APE Jay
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Re: Head Crack

16 Nov 2012 20:13

#558708

The very first Z1s had a larger exhaust seat in them. You could put 32mm valves in them. However, all of them must have cracked from the seat to the spark plug hole, so Kawasaki went with a smaller OD seat to give it more room. But they still do that.

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kzz1king
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Re: Head Crack

16 Nov 2012 21:28

#558723

IMA going to pullmine and check

74 Z1 1075, 29 smoothbores, owned and ridden since 1976
Home built KZ1000 turbo setup

www.kzrider.com/forum/11-projects/532476...s-budget-turbo-build

www.kzrider.com/forum/11-projects/532489-74-z-makeover

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wireman
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Re: Head Crack

17 Nov 2012 00:00

#558736

Ive got several z1 heads and none of them are cracked between the seats,Im not aware of any of my kz heads having that problem either.

posting from deep under a non-descript barn in an undisclosed location southwest of Omaha.

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Galactica
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Re: Head Crack

18 Nov 2012 21:02

#559027

I have a kz900 head with a crack between the exhaust valve and the spark plug on the #3 chamber.

77KZ1000
76 KZ900

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guitargeek
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Re: Head Crack

26 Nov 2012 18:28

#560142

APE Jay wrote: Most of the KZ heads that come thru the shop are like that. Unless you are turboing it of running big nitrous load, you won't have a problem with it.

I was sure glad to read this last night! I had a bad moment when I found these:

1980 KZ750-H1 (slightly altered)
1987 KZ1000-P6 "Ponch"
1979 GS1000 "Dadzuki"

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