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upgrading to a j model head
- Bicycle Lee
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Is there anything else I should know about this upgrade? I just don't want to foul this up this time! :laugh:
1978 KZ1000 police
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- PLUMMEN
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Still recovering,some days are better than others.
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- steve3408
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OOOH...thats doesnt sound good!...a set of 10.25:1 pistons would be a good start since your compression is fixing to drop abot 1.5 points!:laugh:
1980 KZ1000 A4(bought new),1979 KZ1000 MKII(bought new),1978 KZ1000 A (sold)1979 KZ1000 B LTD (sold)1976 KZ900 LTD (sold)1978 KZ750 twin (sold)
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- mark1122
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- Keep twisting it
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76 KZ, frame gusset work,1200CC.Ported by Larry Cavanaugh, 1.5mm.over intakes, Carron Pipe, ZRX12 rear end, and seat,96zx9 front end.
01 CBR600F4i Track bike.
Cobourg, Ont. Can.
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- steell
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Cylinder head.. J model head has larger valves and ports. This head can be used on earlier style cylinder and lower end by installing APE #CCIA cam chain sprocket adapter in head . How to tell which head you have.. Early style heads have four factory drilled and tapped 6mm holes in the center to bolt in cam chain idler gear. Z1 900 heads have 6 mm exhaust studs, KZ1000 8 mm. On the J model head, the four cam plugs at the ends of the camshaft areas are bolted in, on the early style head, they just push in and the valve cover holds them in. The J model / '81-'82 GPZ1100 cylinder head has a larger combustion chamber than the early style head. When these heads are used on the early style motor, a compression ratio drop of about 2 full points can be expected.
More info on the differences between the two motors can be found at www.aperaceparts.com/tech/techkz1000.html
KD9JUR
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- coppertales
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1982 KZ1100 A2
1982 1100 SPECTRE
1982 1100 SPECTRE
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- Bicycle Lee
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1978 KZ1000 police
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- PLUMMEN
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Still recovering,some days are better than others.
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- steell
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KD9JUR
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- Bicycle Lee
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Now I want to ask about jetting.
Does this j-model upgrade change my jetting at all?
I have pods and a stock exhaust on it.
Anyone?
1978 KZ1000 police
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- steell
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I'd like to know about it if you do get it to start.
From the link I posted earlier:
The J model / '81-'82 GPZ1100 cylinder head has a larger combustion chamber than the early style head. When these heads are used on the early style motor, a compression ratio drop of about 2 full points can be expected.
Stock is what, 8.5:1?
Just looked, Zedder says it 8.7:1, so your compression ratio after installing the J head should be 6.7:1.
I'm still curious about whether it will even start.
.
KD9JUR
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- mark1122
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- Keep twisting it
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76 KZ, frame gusset work,1200CC.Ported by Larry Cavanaugh, 1.5mm.over intakes, Carron Pipe, ZRX12 rear end, and seat,96zx9 front end.
01 CBR600F4i Track bike.
Cobourg, Ont. Can.
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~ (k) / (z)
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