1976 KZ900 question / Engine Mods

Hi guys,

I own a 1976 KZ900 that I'm almost done with cosmetically. I'm doing my best to keep the bike looking relatively stock with some nice upgrades. The engine is stock with about 32k on it. I want to build a sleeper that retains a stockish kind of look to it. I was thinking a 1075 kit with cams, VM-29 carbs, port and polish etc etc...

Now, I'm thinking about a 1200 kit or something of that nature. I want to keep my current bottom end. Is this possible with one of the big block kits?

In general I want a bike that can surprise some of the modern day crotch rockets out there.

Any ideas or help would be appreciated.

Thanks,

Austin

The large inch kits cause the bike to run hot on the street and imho should only be used by go-fast types; not those interested in reliability and a pleasant ride. If you soup up a KZ, it will still be slower than the current 600cc class of sportbikes. If you are keen on putting some money into the bike's engine and want to go fast, contact APE Jay, one of our members for advice on a streetable engine.

If you do the 1075 you can use the VM29 carbs if you can find some. The 1200 does not require a big block, but should use 34mm flatslides to get it's potential.

Jay

i agree with wiredgeorge leave the big block/kits for the track guys,as far as surprising sum of the newer sport bikes(crotch Rockets) yes a kz 900/1000 can be built to do this and still be very reliable/pleasant to ride,here's how 1045kit with 10/25 compression,.385 cams,port/polish head,31mm exh/37.5mm intake valves, a set of 34mm flatslides,vance/hines sidewinder with a comp only baffle,dyna coils/ignition,gear it up a bit with say a 40-44 rear sprocket.you can lenthen a stock swingarm 3-4inches spray it black it will look stock to any kid on a rocket,i have this setup on a 1976 kz900 stock bottom end a few other go fast tricks, but if you really want a sleeper this setup will work for you now b4 a ton of guys post let me just say with this setup i beat on the guys in my neighborhood with shiney new crotchrockets 9out of 10 times,yes i'am considered a seasoned rider,when i say i beat them it is on the street lite to lite action i also run this bike ocassionally on the track mine is strutted/lenthened 3in,i run a 18front/47rear sprockets 150/16 rear tire, now again b4 ever says the new bikes will beat us on the turns let me just say this i live in newyork city manhattan there are no hyways here that i cannot run with the newer bikes yes they handle better then our older bikes but unless your on a track it really doesnt matter much,again like i said i have this setup with a few old time tricks i will not give up but this is a solid affordable way to build up a 900/1000.

Post edited by: fastestz1, at: 2006/08/17 18:18

fastestz1 wrote:

i agree with wiredgeorge leave the big block/kits for the track guys,as far as surprising sum of the newer sport bikes(crotch Rockets) yes a kz 900/1000 can be built to do this and still be very reliable/pleasant to ride,here's how 1045kit with 10/25 compression,.385 cams,port/polish head,31mm exh/37.5mm intake valves, a set of 34mm flatslides,vance/hines sidewinder with a comp only baffle,dyna coils/ignition,gear it up a bit with say a 40-44 rear sprocket.you can lenthen a stock swingarm 3-4inches spray it black it will look stock to any kid on a rocket,i have this setup on a 1976 kz900 stock bottom end a few other go fast tricks, but if you really want a sleeper this setup will work for you now b4 a ton of guys post let me just say with this setup i beat on the guys in my neighborhood with shiney new crotchrockets 9out of 10 times,yes i'am considered a seasoned rider,when i say i beat them it is on the street lite to lite action i also run this bike ocassionally on the track mine is strutted/lenthened 3in,i run a 18front/47rear sprockets 150/16 rear tire, now again b4 ever says the new bikes will beat us on the turns let me just say this i live in newyork city manhattan there are no hyways here that i cannot run with the newer bikes yes they handle better then our older bikes but unless your on a track it really doesnt matter much,again like i said i have this setup with a few old time tricks i will not give up but this is a solid affordable way to build up a 900/1000.<br><br>Post edited by: fastestz1, at: 2006/08/17 18:18

what he said,but id substitute an 1197 kit with a stock block to really make it fun!:evil:

the 1197 will tend to run a bit hot in the streets/trffic.

yeah i know,but i like really fast sleepers! thats why i said to use stock block so you still get some cooling between cylinders and also run an oil cooler.ive always had good luck with the bigger motors because you dont need all the high-end stuff like you do with a smaller motor to get decent power.i was gonna go with the 1197 in my z1 and just swap in some 8:1s for the turbo but i decided what the hell a 1385 would really be fun even off the boost! and besides that extra big block was staring me in the face,taunting me!:evil:

Great stuff guys. Here's another question. Could I take the top end and cylinders off of say a kz1100 like the one here?
www.oldkawman.com/gpzparts.html

Would it be basically a bolt in type of deal?

Thanks for all the input.

Post edited by: austin3119, at: 2006/08/17 20:34

why would you want this head?
stick with the 900 head,do the mods i listed and you will be happy!

wireman wrote:

fastestz1 wrote:

i agree with wiredgeorge leave the big block/kits for the track guys,as far as surprising sum of the newer sport bikes(crotch Rockets) yes a kz 900/1000 can be built to do this and still be very reliable/pleasant to ride,here's how 1045kit with 10/25 compression,.385 cams,port/polish head,31mm exh/37.5mm intake valves, a set of 34mm flatslides,vance/hines sidewinder with a comp only baffle,dyna coils/ignition,gear it up a bit with say a 40-44 rear sprocket.you can lenthen a stock swingarm 3-4inches spray it black it will look stock to any kid on a rocket,i have this setup on a 1976 kz900 stock bottom end a few other go fast tricks, but if you really want a sleeper this setup will work for you now b4 a ton of guys post let me just say with this setup i beat on the guys in my neighborhood with shiney new crotchrockets 9out of 10 times,yes i'am considered a seasoned rider,when i say i beat them it is on the street lite to lite action i also run this bike ocassionally on the track mine is strutted/lenthened 3in,i run a 18front/47rear sprockets 150/16 rear tire, now again b4 ever says the new bikes will beat us on the turns let me just say this i live in newyork city manhattan there are no hyways here that i cannot run with the newer bikes yes they handle better then our older bikes but unless your on a track it really doesnt matter much,again like i said i have this setup with a few old time tricks i will not give up but this is a solid affordable way to build up a 900/1000.<br><br>Post edited by: fastestz1, at: 2006/08/17 18:18

what he said,but id substitute an 1197 kit with a stock block to really make it fun!:evil:

And the .384 cams are way too small, even for a 1015, especially with big valves.



Jay

You can't put the 1100 block on a 900 KZ1000 motor. You can do the head with slight modifications.

Jay

Post edited by: APE Jay, at: 2006/08/17 21:18

jay opinions on cams are gonna vary i find my 385x258deg@.040 idle great pull extremely hard up 10-11grand i think alot of guys make the mistake of over camm'n, throttle response is fantastic.

Post edited by: fastestz1, at: 2006/08/17 22:23