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900 Overbore Advice
- jenkrider
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I am seeking a bit of advice from those who have done it before...
There is a LOT of information/mis-information out there about what will work and what will not...
I have a 1976 900 A4 (903cc). It is due for a real re-build. I figure, why go all that way and not improve what I have?
My question is this: What are the options for a streetable 900? I have 900 bottom and top end. I also have a 79' 1000 parts bike in my back yard of questionable history.
I am looking for the best size which doesn't require re-sleeving. I was under the impression that the difference between a stock 900 and 1000 was not the bore but the stroke as changed by connecting rod length. I have been looking at the 1015 kit (Stock 1000?), 1045, and 1075 to mate with my 900 bottom end.
Any advise is appreciated. I know this topic has been gone over before but my search results look like a "what oil do you use" debate
76' KZ900
00' KLR650
82' XV920 Virago
74' Ironhead Sportster
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- Nebr_Rex
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2002 ZRX1200R
81 GPz1100
79 KZ1000st daily ride
79 KZ1000mk2 prodject
78 KZ650sr
78 KZ650b
81 KZ750e
80 KZ750ltd
77 KZ400/440 cafe project
76 KZ400/440 Fuel Injected
www.dotheton.com/forum/index.php?topic=39120.0
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- 80B4
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1980B4 1000
1978 Z1R
1978 B3 750
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- roy-b-boy-b
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1979 LTD Street Fighter.1977 KZ1000
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- turboking
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2005 Kawasaki mean streak
2000 325 H.P. mcXpress turbo Hayabusa
1979 kz 1000 mk II ATP turbo
1975 Z1 960 cc Mr. Turbo
1975 Z1 1428 big block ATP turbo
1976 Kz900 1103 cc ATP turbo
1985 GS 1150E
1983 GS 1100E
1997 Suzuki Bandit 1200S
2001 Kawasaki EX 500 Ninja
1972 Honda cb750 (836cc turbo)
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- Old Man Rock
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Started w/1015cc build, then wanted more umphka... :pinch: Should of just went 1075cc from the start for I have built this engine so many times now it's ridiculous... :whistle:
Take the 900 engine out and have the KZ1000 engine bored to 1075... This way you won't have to bore open the top case for the cylinder sleeves. All internals are for the most part a direct swap, crank, tranny, drive shafts, engine cases etc...
NOTE: W/1075 displacement, definitely replace timing chain, guides, rubber dampers etc....
Replace all engine seals & gaskets. Check the crank bearings as well. If not truly racing, crank doesn't need to be welded for a 1075 build. Yes better if you do and have the funds but not required for normal driving, occasional throttle twisting.
And you'll have a good KZ900 engine sitting there for later use, another build whatever...
You'll gain ~ 200 cc displacement!!! Other than the cylinder 1015 stamping, no one will know for the most part. Twist her up on another bike and they will be surprised how the old girl pulls away on them.
1976 KZ900-A4
MTC 1075cc.
Camshafts: Kawi GPZ-1100 .375 lift
Head: P&P via Larry Cavanaugh
ZX636 suspension
MIKUNI, RS-34'S...
Kerker 4-1, 1.5" comp baffle.
Dyna-S E.I.
Earls 10 row Oil Cooler
Acewell 2802 Series Speedo/Tach
Innovate LC1 Wideband 02 AFR meter
Phoenix, Az
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- jenkrider
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OMR, the only reason I would rather not use that 1000 engine is because it is a shaft drive model and in really rough shape.
Could I use the cylinder jug from the 1000, go to 1075, and put that in my 900 bottom end with 900 head? I guess that is what I am starting to aim at...
And yes, the rebuild will include many new parts as you mentioned. My gear shifter splines are pretty haggard so I might as well go a little deeper and fix that as well.
76' KZ900
00' KLR650
82' XV920 Virago
74' Ironhead Sportster
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- DFIGPZ
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1984 750 Turbo
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- Mercury Kid
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'76 KZ900-Z1 clone
Z1 70's period longbike
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- turboking
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2005 Kawasaki mean streak
2000 325 H.P. mcXpress turbo Hayabusa
1979 kz 1000 mk II ATP turbo
1975 Z1 960 cc Mr. Turbo
1975 Z1 1428 big block ATP turbo
1976 Kz900 1103 cc ATP turbo
1985 GS 1150E
1983 GS 1100E
1997 Suzuki Bandit 1200S
2001 Kawasaki EX 500 Ninja
1972 Honda cb750 (836cc turbo)
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- DFIGPZ
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This is correct some will work some need some minor work.turboking wrote: I've have seen some 900 upper case halves that do require relieving for the 1015 cylinder liners .....some 1015 cylinders will go right on , no problem :blink: ..... depends on the cases. and it's usually very minor relieving :pinch: if needed.. :huh:
1984 750 Turbo
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- jenkrider
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76' KZ900
00' KLR650
82' XV920 Virago
74' Ironhead Sportster
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